


Tangible

by beastofthesky



Series: Tangible [1]
Category: Supernatural
Genre: Alcohol, Alternate Universe - Canon, Angst, Fluff, Leviathans, M/M, Minor Violence, Multi, human!Cas
Language: English
Status: Completed
Published: 2012-05-26
Updated: 2012-07-01
Packaged: 2017-11-06 01:11:31
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 15
Words: 28,249
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/413065
Author URL: https://archiveofourown.org/users/beastofthesky/pseuds/beastofthesky
Summary: <blockquote class="userstuff">
              <p>Wherein Sam's got the Devil whispering in his ear and he's well and truly fucked. Picks up after 7x15 and diverges from canon.</p>
            </blockquote>





	1. Chapter 1

**Notes for the Chapter:**

> I'm fighting a losing war with formatting, so I apologize profusely for any weird spacing where italics are concerned.

Ruby’s knife is really kind of unfortunate to have around. It’s useful, sure – always has been, probably always will be – but it’s also an extremely tangible reminder of the fact that Sam doesn’t always make the best choices.

“Boy, you guys sure know how to pick ‘em,” comes that soft voice. “Couldn’t’ve squatted in a mansion, for once?”

Sam’s been slowly re-learning how to ignore him because ever since that whole Jeffrey-the-serial-killer fiasco, pressing the scar on his palm hasn’t worked. Lucifer is around a lot more often, throwing around snide remarks left and right, and Dean’s noticed a shift in how tense he is but Sam will never, _ever_ admit to what actually happened. He doesn’t even like admitting to himself how easy it had been to just _listen_ instead of ignore, take the (honestly pretty helpful) advice the Devil had whispered in his ear; he doesn’t like thinking about how natural it’d felt to scour through Nora’s exorcisms with him, like they’d been hunting together for years, as if they’d fallen into step beside each other like Dean and Cas had.

So he sighs and scratches a bit of dirt off of the knife’s hilt and doesn’t bother responding. Dean’s probably going to be gone for a couple of hours – there’s a bar a couple blocks away – and earlier he’d firmly planted Sam down on the uncomfortable motel couch, shoved the remote in his hand, and told him to take a night and _relax_.

“Sammy, it’s rude to ignore someone when they’re talking to you.”

Relax. _Right_. Commendable effort, it’s-the-thought-that-counts, et cetera.

What’s worst is that it was a lot easier to ignore when the hallucinations consisted of just flashbacks; Lucifer in the flesh (well, hallucinatory flesh) wasn’t that easy to tune out but now it’s much, much harder – because he’s acting so human or because he _let him in_ , Sam’s got no clue, but it’s irritating. He glares at not-Nick-anymore’s lazy tangle of lounging limbs, briefly, just to acknowledge his not-presence.

Yeah, he’s going crazy.

 

Two more painfully boring hours pass; there’s nothing on cable that’s even vaguely entertaining and Sam left most of his books in the Impala by accident, so it’s either the battered copy of _Hamlet_ or _Crime and Punishment._

Lucifer is still in the room, leaning the chair back on two legs, and Sam’s tempted to snap at him and tell him to Stop That Or You’ll Fall And I’ll Laugh At You the way he always does when Dean does it. He resists (because, honestly, getting smart with the Devil might not be the best idea) and lets his mind wander. It’s a little odd that he feels relaxed now – when Lucifer appears out of nowhere he can practically feel his blood pressure skyrocketing and the panic wraps around his chest like metal bars but after the initial shock passes it’s that same weird easiness he felt when he was scrambling to put the pieces together to find Dean, that weird sensation of finding a common rhythm they both respond to.

Sam checks the time. Dean’s still out and at this point he’s probably not going to be back until the early morning, so it couldn’t possibly hurt, not when he’s already buried this deep in shit–

“Hey Luce,” he says, and the nickname slips out before he can stop it.

The Devil manages to flinch and freeze at the same time and Sam can’t blame him – it’s been a while since he’s talked back and he’s never actually _addressed_ him, much less using a nickname.

“What’s your beef with humanity?”

And if he’s being honest with himself, it’s not just a time-killing question. There’s still a part of him that’s a law student and that wants both sides to every story. Lucifer still has a look of complete shock on his face, something Sam never saw in those 47 years of Hell.

“I’m touched by your curiosity,” he replies, and a smile curls at his mouth as he recovers. “You know, a few millennia in the Cage gives you a lot of time for introspection.”

Sam raises his eyebrows and makes that “and?” gesture with his hands.

“You know the Bible version of the story, right? God creates angels, angels love God, God creates humanity and commands the angels to love humans, Luci protests by loving God more than humans, God sends Luci to the Pit. Yeah?”

“Yeah,” agrees Sam slowly, not quite sure where this is going.

“So put yourself in my shoes,” argues Lucifer, chair back on four legs, voice soft. “You and Dean loved your father more than anything, and you love each other more than anything. One day, your father tells you to love something else – some alien species, not even similar to you – and to put that something above him and Dean and to love it unconditionally, even as it’s flawed and destined to rip itself apart. It’d drive you crazy, wouldn’t it?”

Sam looks down at his hands; the implication doesn’t even need to be said. He’s heard it thousands of times.

_You’re just like me, Sam._

_Our lives are parallel._

_You and I, we’re one._

“Hundreds of thousands of years in Hell with nothing but your own thoughts and some seriously fucked-up human souls wasn’t my idea of fun, but, you know, gives you time to think.”

Lucifer runs a hand through his hair, absently scratches at his scalp in a frighteningly human gesture, and tips the chair back again. “I was jealous of you puny little creatures. I needed you to manifest on earth, and I hated that. You stupid, primitive _apes_ are capable of feeling so much more than angels – you think for yourselves and it tears you apart, but that’s the thing.”

Sam can’t help but notice that there’s an honestly freaky kind of sadness to his smile now. Since when does the Devil get sad? Legitimately sad, not I’m-just-fucking-with-you sad?

“Free will, huh? That’s what I got locked up for, and that’s what you got locked up for. We’re a lot more similar than you’d think.”

Sam’s taken aback by the _truth_ in what the Devil is saying. Lucifer doesn’t lie – oh, how painfully he knows that – so the gravity of this small speech hits him a lot harder than he’d expected. He opens his mouth, closes it, and shakes his head. There’s really no way to respond to that.

“Good enough answer for you?” The smile’s back to being a full-on smirk.

“Yeah,” says Sam again, rolling his eyes and turning off the TV.

He crawls into the lumpy bed and turns his back on the Devil, but for once, it feels like he’s being watched over instead of observed. The thought burrows itself uncomfortably into his stomach.

 

* * *

 

 _He’s shouting your name and asking for more_ , purrs the Impala’s radio, and Sam does his best to just tune it out. Dean’s got that look in his face and he’s tapping his fingers and yeah, he’s totally jamming to this song.

_There’s a devil waiting outside your door._

Normally he’d have no problem with Metallica (or Nick Cave) but this song is hitting uncomfortably close to his hallucinatory tagger-along who – speak of the Devil, ha ha, so funny – is reclining in the back seat of the car, hands behind his head, eyes closed and a lazy smile on his face. The only way this situation could possibly be weirder is if it were real and not all in his head.

_R is for rape me, M is for murder me–_

Nope, that’s it. He lunges for the stereo and ejects the tape, grabs the first one from the box he can get his hands on, and shoves it in instead. Dean looks at him strangely then his face falls when he puts the pieces together. Lucifer shoots him an irritated glare in the rearview mirror. The stereo mulls the tape over and it takes a few seconds for the song to start playing, in medias res–

_–long run, there’s still time to change the road you’re on, and it makes me wonder._

Dean’s knuckles go bone-white on the steering wheel and Sam can see his throat working, trying to swallow.

“Dean?” He takes a short, shaky breath and turns the radio completely off. Sam wonders for a full two minutes what it was that had set off his brother like that (as a rule he never, _ever_ turns off Zep) when it finally clicks that Cas had always put on Stairway to Heaven on those few occasions he’d roadtripped with them. His heart clenches.

“Man, you two should really go see a shrink,” murmurs Lucifer from the back, and his blue eyes are staring at Sam in the rearview mirror. It takes all of his self-control not to snap back that wow, great, that’s not helping at all.

 

The rest of the drive is dead silent save for the low growl of the Impala’s engine; Sam falls asleep leaning on the window and jerks awake when the flames in his head start feeling a little too real. Lucifer is gone from the back seat and it’s a little weird; over the past seven or so hours he’d gotten used to catching a glimpse of him in the rearview mirror or out of the corner of his eye, and now it’s completely empty back there and the fact that it feels weird is _weird_.

He and Dean book a motel room and Dean still isn’t saying a single word – he falls straight into bed and Sam swears he sees the corner of a suspiciously familiar tan sleeve tucked tightly against Dean’s stomach. His heart clenches again because it’s not _fair_ ; the months-old rant runs full-speed in his head, over and over: _he deserved a friend and he got a friend and everything good always gets ripped away from us but not this not_ Cas _not Dean’s best friend not fair not fair_ not fair _Dean always deserved someone like Cas and now he’s_ gone _and it_ hurts _–_

He takes his time brushing his teeth and changing into sweats and by the time he walks over to the unoccupied bed, Dean is snoring softly. He’s halfway under the covers when Lucifer’s voice comes quietly from the corner.

“I forgot you humans do that empathy thing,” he murmurs, as low and smooth as always. “Just another thing on the list of design flaws.”

Sam closes his eyes, breathes in, and breathes out.

“Have you ever considered,” he whispers through gritted teeth, “that if you tried ‘that empathy thing’ you might understand more?”

Lucifer’s face is half in shadow, but Sam can still see the surprise flash across it. He turns his back on the Devil, pulls the musty covers up over his ears, and lets Dean’s snoring lull him to sleep.

 

* * *

 

“Sam, you’re sure you’re okay to hunt?”

If there wasn’t so much pure worry in his voice, Sam would probably have been offended at the condescension.

“I told you, I’m fine,” he repeats for what feels like the thousandth time. Dean raises his eyebrows. “Dean, I swear. He’s not– he isn’t doing anything like that, and he’s easy to ignore. I’m perfectly fine.”

Dean exhales and throws weapons into the duffel with a lot more force than necessary.

“If Cas hadn’t–” He slams the trunk of the car down, practically making the ground shake. “This would never have happened.”

It’s the final straw for Sam.

“Don’t take out your anger on Cas!” he yells, slamming his palm down on the trunk. Dean glares at him.

“Look, I know you’re mad about everything that happened and I know you’re not okay–” Dean opens his mouth furiously and Sam cuts him off. “ _Don’t lie to me_ , Dean, but that’s not the point here! You’re using Cas as an easy out for all of your hurt and your blame and you _shouldn’t_.”

“Sam–”

“What happened is in the past now. I’ve learned to deal with it and you should, too.” Dean’s face is still drawn and pained. Sam knows he can get at least one more comment in. “I’ve forgiven him, you know.”

If he didn’t know Dean better, he’d have said he flinched. Dean turns his back.

“Shut up. Those vampires aren’t going to sit around and wait for us to be done arguing.” He grabs the duffel and starts to head in the direction of where they think the nest is.

“Dean–” He’s pushing now, and he knows it.

“Sam,” says Dean forcefully. He turns. “Look, I–”

He stops, looks away, swallows.

“It’s good that you can still hunt.”

Sam exhales; it’s as much of an apology as he’s going to get.

“Okay,” he says, “so let’s go.”

 

* * *

 

It all happened too fast.

One second they’d been perfectly fine – Dean to his left, slightly ahead of him, quietly creeping towards the vampire nest, and then a phantom voice from behind him had yelled his name and he’d turned around in a panic, machete ready in his hand, but the vamp had been faster and all he could hear was the Devil saying _you_ stupid _son of a bitch, why’d you let them do that?_ right before everything had gone black.

He’d killed his way out of the nest. Evidently neither coven had had any ulterior motives in separating them – the ones that had taken Sam had just wanted a snack, and those that had taken Dean were long headed back to their own nest.

The fact that it had been two covens in the town was what had completely thrown off their hunt, and Sam had been remorseless in killing every one of his captors.

He was in Utah now instead of Texas and if the sinking feeling in his stomach was anything to go by, Dean was probably halfway across the country and trying to figure out the same thing – how to find his brother. Sam had tried calling, of course, but no calls would go through and none of Dean’s numbers picked up. His own phone was long gone, too, and he couldn’t reach any of the handful of hunters he knew.

He’d hotwired a car and booked the cheapest room at the first motel he’d come across, trying to keep calm, not panic because he wasn’t going to let this become another fiasco like the Mystery Spot had been.


	2. Chapter 2

This is what catatonic might feel like, he thinks, or at least an anxiety attack so paralyzing it leaves you comatose. He can’t move, he can’t eat, he can’t _think_ except for _where’s dean where’s dean i need to find him dean where are you i need you i need to find you where’s dean_ and it’s a mantra running rampant through his head.

Lucifer is with him, naturally; over the course of the past four days he’s gone from teasing to snarky to quiet to downright _brooding_ , a dark shadow of frustration pacing a tread into the carpet of every hotel they stay at.

It’s two in the morning, and Sam is sitting in one of the hard, flat chairs, slumped over and staring blankly at a spot on the wall opposite him. Lucifer crosses blurrily in and out of his peripheral vision as he paces. _where’s dean where’s dean where’s dean where’s dean_ –

“Snap out of it,” barks Lucifer suddenly, voice all ice and sharpness, eyes crackling with what looks like fury.

Sam stares at him.

“This isn’t one of Gabriel’s pranks, this is real life, and this is happening right now.” The Devil is practically sparking with static electricity and Sam feels a small thrill of fear, that this vast creature taking up residence in his brain could reach out and touch him – but it’s not real, _Dean_ is real, and his hallucination is right. His mouth goes dry at the realization. “You can figure your way out of this.”

Lucifer steps back and crosses his arms, air still snapping with his whole angelic wrath thing.

So yeah, he supposes it really takes a prod from the Devil to keep him from falling apart. He doesn’t know if Dean would be grateful or pissed.

 

* * *

 

There’s a shifter somewhere in Moab, Utah, and it’s picking off tourists.

Therefore, Sam cannot in good conscience ignore it, and thus finds himself creeping through a dark alleyway in the middle of a city in the middle of fucking _nowhere_ and contemplating whether or not to ask his hallucination (who, by the way, is no less snarky after a fortnight) for a helping hand.

“Make yourself useful,” he whispers to thin air, silver knife held at the ready, “keep an eye out for it.”

It’d taken him all of four days to stop ignoring the Devil, to listen to his advice and to let him help. Now, a good fourteen days after _that_ , he finds Lucifer’s presence comforting. _God help us all_.

There’s a quiet crackle from behind and he knows that’s his hallucination appearing.

“Useful as in ‘the shifter is sneaking up on you from behind,’ or–”

Sam whirls around and lashes out towards the darkly-clothed figure behind him; Lucifer calmly crosses his arms. The shifter screams once at the gash in its arm, lunges for Sam, and gets its throat slit. He steps out of the melting pile of human flesh in disgust and cleans off the knife.

“Thanks,” Sam pants, adrenaline still buzzing loudly in his veins, and it sounds a lot more bare and sincere than he’d intended. The Devil looks mildly taken aback.

 

* * *

 

Apparently sincerity is the trigger for Lucifer to start acting like a god damned five-year-old, filling each successive stolen car with his voice and singing at the top of his lungs and constantly talking, thankfully fading to silence once Sam gets sleepy enough to pass out.

All in all, it could be much worse. It’s when Lucifer starts making snide comments about the fact that he’s separated from Dean that drives Sam to the edge and every day they get sharper, a tangible reminder of the fact that he needs to find his brother. He (well, _they_ , actually) hunt their way through most of Colorado and they’re on the other side of the Rockies when Sam can’t take it any more.

 

“Lucifer, _shut up_ ,” he snarls, but the Devil is still lounging against the dingy wall of the dingy motel, laughing to himself.

“Oh, Sammy, you’re never gonna find your brother at this rate,” he says softly, with that maddeningly condescending smile. “Three weeks? He probably gave up on you.”

That’s it.

Sam whirls on the hallucination and swings a hand towards him, fully intending to hit the wall behind Lucifer, but instead his palm curls around the Devil’s very solid, very _real_ jaw. He can’t move. He’d grabbed Cas before and felt the restrained Grace humming beneath the skin of his vessel but that’s _nothing_ compared to Lucifer. His whole hand goes numb as if he’s been electrocuted and the raw, chaotic power is leaking _everywhere_ , barely contained by the body that’s not meant to be his vessel, not for this long.

Lucifer’s smile widens.

“You’re not supposed to be real,” he breathes, stumbling back. “It’s all in my head.”

“Of course it’s all in your head,” says Lucifer, much too cheerfully. “What was that quote? Point is, just ‘cause something’s in your head, doesn’t mean it’s not real.”

He’s three seconds away from flying into a full-blown panic but a voice in the back of his mind (that sounds suspiciously like Dean’s) is telling him to breathe, calm down, sort this out, make sense of it. It could be another hallucination – he’s seen Lucifer move chairs, pick up books, but it hadn’t affected the real world. Not as other people perceive it, anyways.

But. _But_.

Lucifer is an _archangel_ – however fallen he may be, archangel he is.

It’s completely plausible that the Devil had been hiding himself from everyone else this whole time, appearing only to Sam, like a warped version of Cas’ _profound bond_ with Dean.

“I can see those cogs turning,” says Lucifer quietly, almost proudly. “You’re right, you know. You said yes and you let me in, and now we’re stuck together. When you got yanked out of the Pit, so did I.”

Sam runs a still-numb hand down his face, shakes his head, and pulls the bottle of Jack out of his duffel. He can see Lucifer’s eyes watching as he tips the bottle back.

“So if I die, that means you’re screwed too, right? Right back into the Cage?”

Lucifer nods slowly.

“Alright.” Sam takes another swig and shrugs. “Alright. I scratch your back, you scratch mine, deal?”

“Making a deal with the Devil, Sam?”

There’s a spark of curiosity in his eyes and Sam distantly wonders if every angel has blue eyes – Cas’s were deep, deep blue like ocean waves, and he doesn’t know how Dean managed to keep eye contact with him for more than a few seconds without being overwhelmed. Both Anna and Balthazar had eyes that were a bright, mischievous sort of turquoise; Zachariah’s were ugly, flat, dead-fish-blue. Lucifer’s eyes are clear-sky-gray-blue, bright and strong.

Sam realizes he’s staring, and takes another drink.

“An arrangement,” he corrects, turning around to flop onto the bed. “Don’t– don’t _exploit_ me, or anything.”

He’s almost asleep when it hits him, belatedly, that Lucifer is perched on a chair in the corner with a view of the entire room and that _feeling_ comes back, the feeling of being watched over instead of watched.


	3. Chapter 3

A week later, Sam asks if Lucifer has wings and watches surprise flash across the Devil’s face again.

“I’m still an archangel, Sam,” he replies with a snort. “Doré and Milton got it wrong.”

“Neither Dean nor I could see Cas’ wings,” Sam presses, careful. “He said they existed on a plane we couldn’t comprehend, but I never really asked him about it.” Lucifer crosses his arms expectantly, and Sam takes it as encouragement. “So, I’m going to assume yours are going to be even less comprehensible.”

“Curiosity killed the cat, you know,” says Lucifer, and starts forward. Sam automatically recoils. “Relax. You wanted to see, right?”

He’s thrown for a loop – he’d honestly just been curious about the whole separate-planes-of-existence thing, but offering to show his wings? He’s caught between cautious and curious but he can’t sense any malice in Lucifer’s actions, so he lets the Devil approach him.

Lucifer puts a hand on his forehead and he’s surprised again by how _tangible_ it is, reminded of his actual existence, and then it hits him like a truck.

 

It’s like he was blind before.

He takes a breath and he can sense every molecule in his lungs, feel each one passing through tissue to his bloodstream, racing through his arteries. He blinks and he can feel each eyelash, every synapse firing when he opens and closes his hand – and then he looks at Lucifer.

He’s _glowing_ , brighter than the sun, like the white-hot center of a nuclear blast; brightest angel, indeed. He can see Nick’s body almost superimposed on top of the chaos of the Devil but what knocks him breathless are the wings, because they’re _there_ , he can see them, and there are a whopping _six_ of them. A couple more synapses fire, the valves in his heart thud open and closed, and he remembers a piece of lore stating that archangels have three pairs of wings. They’re pure white, whiter than snow, each glossy feather standing out perfectly to his heightened senses; they’re _beautiful_. He can feel them, hear and taste and smell and a thousand other senses there is no name for but he’s experiencing it all.

Lucifer’s soul – or Grace, or essence, or whatever it is – brushes against his and it’s almost like when he said yes, except this time there’s a clear divide between the two of them and there’s no foreign presence stifling him, mutual instead of parasitic. Their souls are still bound together, since Sam _did_ agree to being his vessel, but now he can tell that the Devil’s manifestation here, outside of the Pit, is a re-creation of Nick’s vessel and there are shining threads running between them, binding and linking and tangling their souls to each others’.

With that contact he’s left with an echo of Lucifer’s thoughts – a whirl of very alien emotions, things that humans don’t feel or think of; patient, coiled rage and hatred, so intrinsic to his personality and his essence that they’re not even a _part_ of his personality and Sam is, somehow, completely able to wrap his mind around the idea. Most of all is the overwhelming _curiosity_. Lucifer is curious about _everything_ – he’s finally out of the Cage again and his vast, alien, angelic mind wants to see and touch and taste and smell and hear it all. He’s not as clueless as Cas, that’s obvious, but for all his hatred towards humanity he’s incredibly curious about _Homo sapiens_.

Lucifer takes his hand away.

Sam is left gaping, breathless, unable to collect his thoughts.

“Oh my god,” he finally croaks when he figures out how to use his throat again.

“ _Devil_ , actually,” corrects Lucifer with a cheeky smile.

Sam is silent for the next couple of minutes, trying to re-organize his brain after whatever the _fuck_ that had been. There are a thousand questions running through his brain but he can’t vocalize any of them, much less figure out which to ask; he focuses on that last, lingering blast of curiosity.

“So the hallucinations, that was just you bullshitting,” Sam says slowly. Lucifer winks. “You know, you could do what Cas did and act like a human.” He tries to suggest it lightly (and fails) because hey, it’d be nice to not look like he’s talking to thin air.

“What, you want me to become a real boy now?” asks Lucifer and there’s seriousness under his mocking overtone. Sam rolls his eyes.

“It’d be nice to not look like a lunatic,” he corrects.

Lucifer looks at him for a good ten seconds, and then snaps his fingers. The air around him ripples for a few seconds like it does on a hot day, and then the Devil spreads his hands.

“Careful what you wish for, Sammy,” he says softly. “Just because I’m real doesn’t mean you’re not crazy.”

 

* * *

 

Sam has slept with the Devil.

It’s not a euphemism, not for comfort, not for warmth – it’s a fact, albeit an uncomfortable one.

Hell was a vicious cycle. It was Michael who’d started the torture, picking on the smallest kid on the playground, the most negligible threat, while Lucifer raged and screamed and beat against the walls of the Cage with everything he had. Michael would torture and get bored, torture and get bored, over and over, and in the lulls of Michael’s boredom Sam would collapse in a corner in the closest approximation of sleep possible in Hell.

The first time Lucifer had curled himself around Sam’s miserable form he’d panicked; that was the _Devil_ , pressed in a line against his back, too hot and too cold at the same time. Lucifer would lie there and murmur things; nothing in particular at first, sometimes things in Enochian, and then he would start to praise Sam. It was grudging praise, at first, for having the strength to release him from the Cage in the first place, for resisting his possession, for coming up with the idea of getting him back in. He would tell Sam about how similar they are, two parts of a whole, two souls meant to be intertwined. Sam would keep quiet every time, not trusting himself not to scream the second he opened his mouth. Lucifer would slowly get angry with him, upset at the lack of response, and he’d start whispering cruel things to him, things he’d tried his hardest to escape from and push away, things that make him want to scream and cry – the start of a downhill slide that would lead to torture just as bloody as Michael’s.

And then things would bend and shift and snap and Sam would be left watching Michael and Lucifer rip themselves to shreds, flesh lying scattered on the bloody floor of the Cage, bones snapping, curses in Enochian making his ears bleed. That always managed to be the worst for Sam – he’d had his spats and fights with Dean, of course, and they’d beat each other up before, but to watch two brothers destroy themselves like that, over and over, was utterly incomprehensible and devastatingly painful.

Lucifer would crawl to him after the fights, shaking and bloody, sometimes the winner and sometimes the loser, and he would mold himself to the curve of Sam’s back. He’d resisted wildly the first time Lucifer’s consciousness had brushed against his own, scared of being tortured and hurt and used – but he’d pitied the Devil once, let him in, let him take comfort in Sam’s memories of a loving older brother, and from then on he’d let Lucifer in every time.

Then Michael would grab a fistful of his hair, yank him to his feet, and the vicious cycle would start again, over and over, forty-seven years of being a rag doll.

 

So, really, he shouldn’t be _this_ surprised when he turns off the light and slides under the covers only to find a debatably corporeal vessel reaching absently for his waist.

“Uh–”

He has no idea what to say right now.

_"Sorry, we’re not in the Pit any more so it doesn’t work like that?"_

_"Sorry, I don’t want to be spooned by the Devil?"_

His stupid brain makes the unfortunate association between Lucifer’s weight and not being tortured so his body relaxes of its own accord. Sam swallows and gives up. He thinks it may have become routine for Lucifer too, and he takes a second to heave a self-deprecating sigh. His life could not _possibly_ be weirder.

“Do you even sleep?”

“I can if I want,” says Lucifer quietly and Sam’s struck again by the utter _weirdness_ of everything. He almost wants to go bang his head against the wall but it’s been a long day and his skin is still tingling from that venture into whatever dimension Lucifer normally functions in and as much as he wishes he was alone in the room, his eyelids are heavy as stone.

He doesn’t dream of Hell.


	4. Chapter 4

Lucifer is draped, cat-like, across the couch and watches every movement Sam makes as he repacks his duffel. It’s not hard to disregard him, automatically, as a result of constantly having shared a room with Dean.

“How do I know you’re not going to just– _mojo off_ on me one day and re-start the Apocalypse?” Sam swallows, hard, and hopes his fear isn’t obvious. Lucifer looks at him like he’s stupid.

“Sam, I am _bound to you_.”

He pronounces each syllable clearly, as if Sam were a simpleton. It’s an insult to his intelligence, he thinks distantly.

“You’re my vessel. I might be wearing a different meatsuit, but I can snap my fingers and go to China just about as easily as your liver can.”

Sam exhales.

“So you’ve got nothing? No juice?” he asks, hopeful. The Devil blinks slowly, eyes never leaving his, and Sam is suddenly hit with a reminder that he’s snarking at an entity that is older than he can possibly comprehend.

“Oh, I’ve got juice,” says Lucifer icily, “but your oozey friends? They don’t like me very much. I want them to find me just about as much as you’d like them to find you or Dean. I scratch your back, you scratch mine.”

Sam can feel the corner of his mouth quirking up. “You’re scared of them.”

“What can I say?” The Devil spreads his hands innocently. “Bastards are good at making dead what they want to make dead. Better to stay out of their way for now.”

Sam looks at him, eyebrows up, then scoffs and zips up his duffel.

 

They’ve got a lot of miles to cover.

 

* * *

 

He shrugs on his jacket even though it’s not that cold a night, makes sure his wallet is in his pocket, and grabs the motel key.

“Don’t start the Apocalypse,” he mutters, and reaches for the door.

It’s past 11, nearly midnight, he’s been driving all day, Lucifer is doing a great job driving him up the wall, they've still got no leads on Dean, they're still miles away from the house in South Dakota that's their goal; he’s perfectly allowed to be as cranky as he wants.

“ _Sam_.” There’s something stern and almost Dean-ish in Lucifer’s voice so he turns, eyebrows furrowed. “At least take a knife, you dolt.”

There’s an odd sort of stubbornness to the Devil’s borrowed face. Sam crosses his arms and tries not to smirk.

“You’re worried about me,” he says shrewdly.

“Can’t have you getting killed off, can I?” answers Lucifer, face carefully neutral. “I wouldn’t have any company.”

Sam shifts uncomfortably because, _awesome_ , he’s actually touched by the fact that Lucifer is concerned for his well-being. Half a decade in  the Cage with him and he knows how to read the guy probably better than anyone else, save for Michael; Lucifer’s showing genuine concern and trying his best to hide it.

Sam shakes his head and digs in his duffel, trying to hide what probably looks like a sardonic smile.

The air is pleasantly cool on his face with just enough sharpness to warrant the jacket that’s hiding the knife. The neon open sign is flickering a little miserably from across the street but it’s food and Sam _really_ isn’t feeling picky right now.

There’s an alleyway to his left, a little ahead of him, and as he draws closer the stark blackness of it registers as suspicious but before he can do anything, something grabs him and slams him bodily against the wall. Two, three punches – the blood’s already dripping down his chin. The hands release him.

“Well, well, well,” rasps a voice, and Sam takes the opening to draw the knife instinctively, gratitude towards Lucifer flooding him. “Looks like I caught me a Winchester for dinner.”

His blood runs cold.

The smile on his attacker’s face is a little too wide, a little too inhuman and too hungry, and he knows in the pit of his stomach that it’s a Leviathan. On his own, he’s completely and utterly _fucked_. He has no sodium borate, no gun – hell, the knife he’s got probably won’t even chop its head off but like fuck he won’t go down fighting.

The Leviathan steps in and Sam takes his chance, snaps the knife out in a wide arc, but the cut is too shallow. Pain flares and then his whole forearm goes numb; the knife clatters to the ground and the Leviathan snarls wordlessly, pressing one hand to his throat in an attempt to stem the flow of black. With the other hand the monster-cum-human grabs Sam’s throat and slams him into the ground so hard his vision goes white and his windpipe is dangerously close to having collapsed.

He closes his eyes tightly in an attempt to clear his vision and there’s an inhuman hiss; when he opens them someone that looks awfully like Lucifer is standing in front of him, machete held casually in one hand and with a set in his shoulders Sam knows from Dean as the Defending Someone kind. His head is on fire and he knows he has to be seeing things. The last thing he can comprehend before blacking out is Lucifer settling into a protective crouch over him.

 

* * *

 

“Rise and shine, Sammy.”

He jerks awake and instantly regrets it; the muscles in his forearm scream in protest and he’s mostly sure he has a concussion. Lucifer is smiling placidly down at him.

“Leviathan?” he spits out between gritted teeth, not willing to make the effort to string together a sentence.

“Drowned in acid, head chopped off and thrown in the river, body dumped in a construction zone,” lists the Devil, off-handedly, and before Sam can react (much less _move away_ ) Lucifer reaches down and hauls him up by the shoulder, as if he weighed nothing. “You’re a wreck.”

There’s a note of steely reproach in his voice, and Sam is too tired to protest Lucifer looping an arm under his shoulder. Coldness radiates from him with the smallest hint of dangerous anger and Sam knows it all-too-well from Dean; it’s silent until they get back into the motel room and suddenly he’s being shoved roughly against the door.

“Wh–”

“What the hell was that?” snarls the Devil. It’s exceptionally intimidating because the room is dark and the only light is from the street lamps outside; Lucifer’s eyes are burning. “How could you’ve let your guard down like that, even for a second? You’re a hunter, Sam, you were raised better than this. Your life is always on the line, so you better act like it.”

He lets go of Sam’s jacket and throws himself broodily onto the couch; Sam swallows nervously. This is dipping into extremely dangerous territory that he _does not want to explore_ , territory that has every one of his instincts screaming bloody murder.

He pushes it completely out of his head and goes to wash the blood off of his face before crawling straight into bed, pausing only to ditch his jacket, shoes, and jeans. He wants to pass the fuck out but his brain _will not shut up_. He can’t get the image of Lucifer standing over him out of his head, the way there was protectiveness written in every line that he’s always been used to from Dean. And sure, okay, if he dies then they’re both going to be sent back to the Pit, but there was an _otherness_ in the way Lucifer had defended him and it is utterly scary as _fuck_.

“Why’d you do that?” He gingerly throws an arm over his swollen face and rolls onto his back.

“If you die, we’re both back in the Cage,” says Lucifer and Sam can practically _hear_ him rolling his eyes.

“No shit,” he grouses back, and turns to look at him. “You know what I meant.”

It’s been over a month and all residual strangeness re: Sleepovers With Lucifer has subsided. If Sam _really_ thinks about it then yeah, okay, maybe this is a little fucked-up, but desperate times, desperate measures. He knows Lucifer can cripple him at any moment and haul him around like a meat sack but after decades of being stuck together he _knows_ there’s some kind of twisted, creepy Stockholm syndrome stuff going on.

The Devil’s eyes are blue and steady and old.

“It’s what you woulda done for Dean,” Lucifer replies. “It’s what Michael–” And he stops, blinks, and leaves the thought hanging. Sam thinks he knows what would have come next (starts with a _sh_ and ends with an _oulda_ ) and his heart twists uncomfortably. “You’re a good brother, Sam.”

“Michael wasn’t,” says Sam quietly, staring back up at the ceiling.

“Neither was I.”

“I pulled Adam into the Cage,” Sam whispers, (almost) completely non-sequitur, and the weight on his chest lessens slightly. It’s been haunting him ever since he got his soul back and the confession, surprisingly, eases some of the burden. Out of the corner of his eye, he can see Lucifer raise his eyebrows.

“Michael burned Adam out completely,” he says. “That wasn’t your fault. I spared you. I like you, Sam. You’re interesting.” Something about the way he says it makes Sam’s stomach twist uncomfortably again. “Adam made his choice. You never killed a brother. I did.”

Sam looks at him again, and he’s shocked to see the pain written in Nick’s features.

“Wh– Gabriel?” It’s Lucifer’s turn to roll onto his back and he thinks it might be some kind of dumb _vessel connection_ , but the sadness and loss and regret are practically tangible. Sam touches his shoulder, very lightly, and hopes some of his empathy is communicated.

“Luce,” he says quietly, after ten minutes pass. “Thanks for saving my life.”

Lucifer shoots him a sidelong look then winks.

“Warming up to me, huh, Sammy?” He makes to turn towards him again, ending the conversation and suggesting Sam go to sleep; Sam is a millisecond away from turning onto his side, too, when it hits him that this had kind of been A Moment and he should do something.

“Other way,” he says, and lightly pushes Lucifer’s shoulder away. There’s a look on Lucifer’s face that Sam’s never seen before, and he has no idea what it is or what it’s supposed to be. It’s surprisingly easy to curl himself around Lucifer, drape a hand in the curve between the borrowed-stolen hips and ribs, let his forehead brush against messy hair. He smells faintly of petrichor and the smell Sam associates with blizzards and lightning and being outdoors, nothing of the sulfur-hellfire-brimstone-dried-blood of Hell. His head is still pounding and the last thing he registers before falling into a dead sleep is that Dean would probably kill him.


	5. Chapter 5

He’s nervous as _fuck_ , pulling into the street – of everywhere they’ve been so far this is the place Dean is most likely to be, and he can’t stop his heart from pounding with anticipated disappointment. There’s no car in front of the house but the garage opens into a back alley so it’s a 50/50 shot.

Lucifer is unusually (read: mercifully) quiet this time, no taunts or teasing. His legs carry him up the steps to the door and he figures he should knock first, just in case, but he keeps a hand on the pistol inside his jacket. Lucifer is somewhere behind him, looking much too nonchalant with his hands in his pockets and Sam counts ten, twelve heartbeats, and the door swings open.

Relief floods him.

“Sam? What the– _Sam!_ ”

Dean pushes past him and draws his own pistol and Sam’s blood runs cold when he realizes he hadn’t planned ahead at all as far as explaining Lucifer.

“Dean, wait, I can–”

“Dean?”

The two of them turn around, Dean’s gun still pointed at the still-much-too-relaxed Devil, and Sam’s jaw drops.

“Cas!”

Because it’s _Cas_ standing in the doorway with that same intense glare but something’s different – the crackling intensity is diminished, he’s wearing what looks like some of Dean’s (rather ill-fitting) clothes; there’s tape around one set of knuckles and a still-healing cut on his cheek and he realizes Cas must be _human_.

“Sam,” snarls Dean, dangerous, “how about you tell me just what the fuck is going on?” He looks back at his brother and Dean looks like he’s about to blow a fuse, especially compared to Lucifer’s magnificent indifference.

“Okay,” he says, hands up, in his best placating tone. “How about we put our weapons away, go inside, and trade stories? Because, honestly?” He gestures helplessly at Cas, unable to find words for the whirl of _how the fuck_ in his chest.

 

* * *

 

Roughly five hours, fourteen beers, and three bottles of whiskey later (Lucifer seems to have the same kind of monstrous tolerance Cas used to have) everything has been laid straight. There's still All The Details and Are You Sure It's Okay and What Really Happened to sort out, but Sam’s been driving all day and he’s absolutely beat. Dean is staring moodily at the cluster of empty bottles on the kitchen table; Sam knows any conversation for the rest of the night is going to be pointless small talk.

“Any functioning bathrooms?” he asks. Dean looks up at the question and the ghost of a grin flits across his face.

“What, you think we were bumming around in this house for the past two weeks?” he shoots back. “Running water, gas, electricity, the whole nine yards.” Sam raises his eyebrows, impressed. “Not much furniture, but–” He shrugs. “We’ll get there.”

“Alright.” Sam exhales. “I’ll, uh, grab my stuff and hit the sack.”

  
  
It’s incredibly nice to take a shower after an entire day of driving and while even a motel bed is preferable to sleeping on the floor, nothing can quash the happiness of knowing that Dean is safe and that Cas is back and that, for now, everything is okay.

Just like there’s something innately _different_ about a human Cas, Sam can tell that something’s different about Dean now, too. His brother seems lighter now, like less of the world’s weight is crushing him; the wrecked look in his eyes is gone and Sam is absolutely sure that it’s because Cas is back. Maybe, just maybe, they might be getting the the point where life stops taking things away and starts giving them back.

The living room is dark save for the dim light of the TV when he walks in, and the sight greeting him is so unexpected and pleasant that he leans against the door frame and grins like a kid. Cas is absolutely _passed out_ on the couch, breathing softly and curled in on himself like a cat, but what’s making him smile is Dean, kneeling over him. He can’t be too sure, but it looks like Dean’s got one hand cupping Cas’s face. Odd.

“C’mon, man, I can’t let you pass out on the couch,” he murmurs, and pushes a tuft of dark hair up off of Cas’s forehead. Sam can barely hear him, but the next sentence sounds awfully like, “Cas, you big baby, wake up.”

He’s both unimaginably touched and annoyed; Dean’s usual method of waking him up generally involved a lot more hitting and loudness but at the same time, he thinks Dean might actually be Showing His Feelings. Cas sits up slowly, half of his hair flattened and the other half sticking up, and Sam catches a glimpse of his brother’s smile.

He clears his throat.

“I wanted to let you know I took the bedroom right next to the stairs,” he says, trying to keep the grin off of his face. Cas drags a hand down his face, yawns, and stands up; Dean follows suit and Sam swears he’s got a hand on Cas’ back.

“And, uh, _Satan_ _?_ ” Dean’s bitchface is as potent as ever. “He need to take a nap after apparently _not_ wreaking havoc?”

“Oh, I’ll be fine in the library,” says Lucifer, walking in from the kitchen with his fingers keeping place in one of Bobby’s old tomes. “The amount of bias in the Bible is fascinating.”

“Yeah, whatever.”

Dean rolls his eyes and pushes past Sam without so much as a goodnight; his footsteps are heavy on the stairs and Sam sighs. Cas rubs his forehead.

“Goodnight, Sam,” he mumbles. “For what it’s worth, I’m glad to see you well.”

Sam puts a hand on his shoulder and takes a millisecond to reflect again on how _human_ he feels – no thrum of Grace and no latent static electricity under his skin, especially not compared to Lucifer.

“Cas, I’m really glad you’re back,” he replies, and he means it. He tries to find a way to tell Cas about how happy he’s making Dean (well, maybe not happy at the moment) but realizes that Cas probably knows and for now, he should probably let it rest. _Especially_ if his brother and Feelings are concerned. Cas smiles at him, tired, and follows Dean up the stairs.

 

* * *

 

He’s acting like a child and he knows it.

Even with (and in spite of) Sam’s track record of Making Exceptionally Bad Decisions, this one takes the fucking cake and the rest of the party with it. A small part of his mind is telling him that maybe this time, with the Devil on their side and not working against them, they might be able to win this fight; he knows it’s logical and that he should calm down, work on keeping his temper or whatever Zen crap Sam would normally spew, but he lets himself fester in vindictive frustration _because he wants to_ and he _can_.

There are quiet footsteps nearing his doorway so he turns his head the other way, arms under the pillow, stomach flat against the old mattress. The hinges squeak quietly when Cas pushes the door open ( _not_ that he knows what Cas’s footsteps sound like or anything) and then there’s the quiet rustle of clothing as he changes.

“Dean.” His voice is sleepy and rougher than usual and Dean hunches his shoulders; he suddenly feels guilty for acting so petulant but then again, he sort of has the right to. The mattress shifts as Cas sits down behind him.

“Sam’s not misguided,” he murmurs, and pulls the shirt down absently over Dean’s hips, straightening it out, hand lingering. He hadn’t realized it had even ridden up in the first place. “My insight might not be worth much any more, but I believe Sam is safe. Lucifer has no bad intentions, and he might be able to provide some information on the Leviathans.” He pauses; his hand is still on Dean’s back, warm and solid. “This wouldn’t even have happened if I hadn’t broken his wall.”

Dean sits up.

“Look, Cas, we’ve talked about this,” he says quietly. “He’s doing a lot better than he was before and you said it yourself, you don’t think Lucifer’s gonna screw with him for now.” And it’s happening _again_ and he can’t stop it, where he throws everything else out the window in order to defend Cas. From _himself,_ no less. He doesn’t know how his hand ended up on Cas’s shoulder but it’s there and Cas is curling in towards him.

“You are much more than I deserve,” Cas whispers, and it’s murmured against his collarbone as he gets an armful of ex-angel.

Dean’s heart is lodged somewhere in his throat and his stomach is in knots as he pulls blankets over both of them; he can’t help but reach out and bury himself in Cas, twist their limbs together and push himself close enough to feel his heartbeat. It’s disgusting, how needy and clingy and dependent on Cas he’s become throughout this whole mess, but it’s all worth it to know that somehow Cas has managed to bury himself in the same kind of hole.

Neither of them can sleep alone. They know – they’ve tried on multiple occasions to grab a double at a motel but it always ended up with Dean fidgeting and tossing and turning until Cas quietly slid under the covers with him, perching himself on the very edge of the bed. It’s crawling dangerously towards dependency and Dean can’t do anything to stop it.

He takes a deep breath and Cas presses a rare kiss to the side of his head – his heart speeds up by a factor of about seven and he’s terrified, he has no idea where this is going or what to do, but what he does know is that he cannot, will not lose Cas again.

“Dean?”

“Hmm?” Cas hesitates and pushes himself up on one elbow; Dean follows suit.

“I’m–” He’s having a hard time finding words and it’s _weird_ , because Cas is always so calculated with everything he says. “I still don’t know what this is, this... thing I’m feeling. It’s human.” Dean’s mouth goes dry. It’s the one topic he’s the worst at talking about (or even silently acknowledging) but this is Cas and he feels obligated to explain or at least say _something_.

“Honestly?” He can hear his voice breaking slightly; he can’t remember the last time he was so nervous. “I don’t know, either.”

There are so many things bottled up in his throat (don’t leave me again please i can’t deal without being with you again stay stay _stay_ ) but he can’t make himself say any of them so he reaches forward, pitifully, pathetically, and pulls Cas close against him. His hands are pressed tight against Cas’s bare back as if he can actually, physically hold him there, keep him from going away again; part of his brain is dully registering the fact that hello, Cas is shirtless, but he firmly shuts down that thought. Somehow Cas is holding him just as tightly, arms warm and strong and _human_.

“Cas? You know, it doesn’t change anything that you’re human. I still– you know.” All of the words are getting stuck in his throat and his mouth and nothing is coming out right. “You’re still Cas, and I–”

Cas sighs, runs a hand through Dean’s hair, and he knows it’s a silent _you can shut up now_.

“I know.”

He can hear the smile in his voice and his stomach twists when Cas leans down again and presses another light, lingering kiss to his forehead. He falls asleep to Cas’s fingers rubbing soporific circles into his scalp.  


  
  
The smell of old blood and sulphur and rotting flesh suffocates him and his hands are wet with blood, covered in entrails; screams are echoing in his ears and suddenly his shoulder is burning burning _burning_ –

He jerks awake, chest heaving, and realizes that Cas is grabbing his shoulder right where his handprint is burned into Dean; he’s drenched in cold sweat and the fear-adrenaline is still pounding in his veins. Cas pulls him close, rubbing a circle into his back with one hand, murmuring his name over and over, breath warm against Dean’s neck. Dean takes a deep, shaking breath and clears his throat.

“It’s been a while,” he whispers, voice hoarse with sleep.

“I know, Dean, I know,” Cas whispers back, voice muffled in Dean’s hair, and _of course_ he knows; Cas knows more about him than _Sammy_ does, Cas has held his soul and put it back together, Cas knows the worst of him and still takes care of him when he’s had a bad dream. He kisses what he can reach (somewhere between Cas’s shoulder and collarbone) and hopes the gratitude is evident because he’s got no idea how to verbalize the knot in his chest and somewhere along the way he realizes he should do that more often, that it’s okay to be grateful, and that for once, he has everyone (living) he cares about under one roof and _it’s okay_.

“Cas?” He disentangles himself to look the ex-angel, ex-fallen angel, ex- _god_. His eyes haven’t lost an inch of their gravity. “Thanks. For– for everything.”

Cas smiles and there’s a bit of he finally gets it in the way his lips quirk up; Dean clumsily presses a kiss to his forehead (ignores the way his stomach twists) and pulls Cas close against him. He sleeps, dreamless, for the rest of the night.  
  
  
  
“Cas?”

It’s the first word out of his mouth, the second he wakes up; a plea and a call and a need. It’s murmured against Cas’s stubbled jaw as he leans over, chest still pressed tightly to his ex-angel’s back, hand still curled around Cas’s hips. He acknowledges the fact that his brain is screaming right now, _this is dangerous territory_ and _get out while you can_ , and he stubbornly ignores it.

“Hey, Cas.” This time he gets a response: a quiet groan that translates into _let me sleep_. He chuckles and lightly runs the back of his hand down Cas’s face.

“Sleep is a terrible concept,” Cas grouses, morning-voice hoarse. “I don’t understand why something this mundane and addictive has to be so necessary.”

And with that he pulls the comforter tightly around himself and buries his face into a pillow.

“C’mon, sweetheart, you can’t waste the whole day sleeping,” Dean says, still chuckling, and stretches as a yawn catches him mid-word.

“Yes, I can.”

“Yeah, but I won’t let you.” He has no idea when their friendship (oh, _friendship_ , yeah _right_ – he should really stop kidding himself) dissolved into this pointless, schmoopy, _sappy_ banter and he should, by all means, be disgusted by it and stop immediately. Instead he puts a hand on Cas’s shoulder and rolls him over with little resistance; Cas is smiling and he can feel the corners of his mouth quirking up in return and christ, he is _really close_ to Cas.

The moment’s over when Cas stretches like a cat, arching his back and twisting impossibly to the side. Dean shakes his head, still smiling, and stands. The wooden floor is cold against his feet but he ignores it; Cas’s hair is ridiculously messy as he tugs on a pair of jeans with a hole worn through one of the knees and shuffles his way to the door. This is Dean’s favorite part of the morning – seeing Cas still sleepy and warm and pliant, so _different_ from the hardness of when he was still an angel, so utterly human, and yet so completely _Cas_.  
  
  
  
Cas makes a beeline for the coffee pot and it’s burbling within seconds; he drums his fingers almost impatiently against his mug and Dean hides a smile as he waits for the pan to heat up.

It’s a little scary, how domestic and routine this feels. He makes to move past Cas to the cupboard but something catches in him and he finds himself curling a hand around Cas’s waist, leaning in and pressing a kiss to his jaw. The more he thinks about last night ( _thinks about_ , not dwells on, because he doesn’t _dwell_ on things like this) the more he realizes that he should do something about it; something feels different and it might have to do with the fact that he got dangerously close to verbalizing how he feels.

Cas turns around with surprise in his baby blues and Dean realizes that this is crossing into a level of intimacy they’d never really touched before. He’s close enough to see the darker flecks in Cas’s eyes – close enough to see the pattern of veins on his eyelids, close enough to trace the curve of a cheekbone, just _close_. Cas is searching his face and it’s times like these Dean forgets he’s not an angel any more; his eyes hold the same amount of gravity and that same probing depth.

“Dean,” says Cas quietly, and something in his voice sends a shiver down Dean’s spine. “I’m going to kiss you.”

Before he can react there are hands on either side of his face and Cas gently presses their mouths together.


	6. Chapter 6

There’s more than enough space for his precious few things in the room; Sam dedicates one corner to his clothes, one for his shoes, and takes up a whole wall for the three rugs and four blankets he’s using as a makeshift bed. Last time he’d checked Dean’s light was still on, a glowing strip under the doorjamb, but whatever other room Cas must be using is dark. There’s a soft glow coming from the library-room downstairs and Sam sighs, then closes the door. He’s just about to resign himself to sleeping alone (and at the same time, berate himself for not being used to sleeping alone) when he turns around and Lucifer is sitting down against the wall, book propped up against his thighs. The corner of his mouth twitches up in an unwanted smile, and he flicks off the lights before crawling under the blankets, face-first into a pillow. Lucifer is cool-warm next to him and smells like old books.

“I hope this doesn’t end up as bad as the Ruby thing,” Sam mumbles into the pillowcase.

“Yeah, but Ruby was a manipulative bitch who hooked you on demon blood,” responds Lucifer, dog-earing his page. "I'm just the Devil." Sam snorts.

“Hey, she was _your_ manipulative bitch.” Lucifer is under the covers now, on his back with his hands behind his head. “All I can do is try and convince Dean that you're not here to kill us all, I guess. At least Cas is on my side.” He pauses for a second. “I think.”

Lucifer snorts softly.

“Your brother looks at him like he put the stars in the sky,” he says, a little wry.

“Cas died for us,” says Sam absently. “For Dean. Multiple times.”

The implications are left unspoken.

Sam had discovered roughly a week ago that some kind of ridiculous vessel mojo connection lets them do a sort of communication thing; it feels to him kind of as if one of the many planes between them disappears and they’re allowed to brush together, almost like the time Lucifer let _him_ in, let him see his wings and see the world as Lucifer sees it. With a very human sigh Lucifer turns and wraps an arm around his shoulders. There’s a spark when his wrist brushes against Sam’s biceps, a bright-blue discharge of static electricity, and Sam flinches automatically inward then promptly flies into a quiet panic.

If he’s being honest with himself, it’s the ease of the situation that’s freaking him out the most. How easy it is to curl against the Devil’s frame, how easy it is to drape an arm around his back in return, how easy it is not to resist, how _easy_ it is. He suspects Lucifer breathes and has a heartbeat just to humor him but it’s comforting nevertheless, listening to sounds that are human as he falls asleep. He can feel Lucifer’s face buried in his hair and there’s a satisfied hum that resonates somewhere deep in his bones, some intrinsic part of him that’s responding to the fact that Lucifer has an arm hung lazily across his hips and that Sam can feel stubble rasping lightly against his forehead. When he falls asleep, it’s light and easy and he doesn’t dream.  
  
  


Sam’s awake with a jerk.

The room is still dark and his internal clock puts the time at around 3, 4 in the morning – it takes him a couple of seconds to realize what’s so different. Lucifer is curled loosely around him and he’s inches away from a stubbled neck; his mind is still hazy with sleep so his first, childish reaction is to lean forward and place a little-boy’s-kiss under the Devil’s jaw like he used to see Dean do, standing on his tiptoes to kiss their dad goodnight after pulling a blanket over him, slumped in a motel chair, drunk. Lucifer doesn’t move, but there’s a hum that runs through his bones and Sam closes his eyes again. He’s spent the past few weeks dwelling on what Lucifer had said to him, just before he’d thrown them both into the Cage – how they’re two parts of a whole, how they were made to fit together since light was let be. The more he thinks about it, the more it’s dawning on him that while he might not like it, it’s _true_.

“So maybe you’re right,” he mumbles, still half-asleep and falling, falling, falling. He can feel Lucifer shift a bit around him.   

“About what?”

But Sam’s warm and comfortable, curled against Lucifer (even though he’ll deny it later, of course), and he’s asleep again before he can manage an answer. Lucifer sighs impatiently and runs a hand through Sam’s hair, just once.  
  
  
  
He knows instantly that he’s slept in, and by a lot; the sunlight hitting him in the face is too muted for it to still be early morning. His watch reads 9:37 and he groans.

“Rise and shine, Sammy.” Lucifer is leaning against the wall, arms crossed and with one of his shit-eating, cheerful smiles. “Thought you needed some beauty sleep.”

“Yeah, well–”

Sam doesn’t have a coherent retort, not this soon after waking up, so he rolls his eyes and gets up. It smells like coffee and food from downstairs and it’s the sole thing motivating him to actually get moving; the novelty of having a room under the same roof as Dean hasn’t worn off and a big part of him wants nothing more than to laze around in bed for the better part of the morning, however completely against his habits that might be.

Lucifer follows him around idly as he dresses and brushes his teeth and washes his face; he’s like a cat, wandering absently after him, except most cats don’t hum Stairway to Heaven (complete with guitar solo) under their breaths. By the time Sam walks downstairs Lucifer is back in the library and buried under a stack of books.

Either Dean or Cas must be frying eggs in the kitchen because the smell and the sound are making him salivate; he turns the corner and yeah, Dean is guarding the frying pan while Cas nurses a cup of coffee. He announces his presence with a ‘morning’ and reaches past Dean to throw two slices of bread into the toaster. He and Cas have a sort of comfortable quiet thing going on – that and Dean’s _niceness_ last night have him wondering exceptionally hard exactly what happened in the seven weeks that Dean skimmed over and whether Dean’s doing his emotionally-handicapped thing. He’s surprised at the fierce protectiveness that flares in him; he’s worried about Cas, whether Dean’s going to accidentally do or say something to hurt him, and it’s the same kind of protectiveness he’s sure he’d feel if he were an older brother. At the same time, though, he’s happy – Cas and Dean have obviously resolved their post-God-complex differences and it’s _so good_ to see Dean looking like the world isn’t crushing him.

Lucifer walks into the kitchen right as Sam pours himself a cup of coffee. It’s interesting, he notes, that Dean bristles immediately and moves himself between both Cas and Sam, very much an Overprotective Big Brother.

“Busy night there, Satan?” asks Dean, poison in his voice. “Awful lot of reading you’ve got to get through.”

“Oh, I didn’t spend the whole night reading,” Lucifer replies, with a smile that looks like it’s making Dean’s temper flare dangerously. “I took it upon myself to ward this house, since you schmucks didn't.”

Sam blinks, surprised. Lucifer snaps his fingers. Every single wall is covered from floor to ceiling with sigils, some of them in chalk and some in what looks like blood. Cas is whirling around and it’s almost comical, how astonished he looks.

“But these–”

“–Will hide this house and anyone or anything in it from any supernatural or paranormal creature.” Lucifer interrupts him smoothly, and snaps again; the sigils disappear.

Sam is suddenly filled with something he can’t really name – it’s a mix of gratitude and amazement and pride, maybe, and he knows Lucifer can feel it because he looks at him and a flash of surprise flits across his face, too quickly for anyone but Sam to notice.

“How do we know you’re not lighting this place up like a beacon for any monster that wants us dead?” fires back Dean, still completely on edge.

“It’s the truth,” says Sam, and at the same time Cas replies, “I recognize these.”

Dean glares at the three of them in turn, then slides the fried eggs onto three plates and throws his own onto the table a little too hard.

“ _Fine_ ,” he growls. Sam raises his eyebrows at Cas, who shrugs and sits down opposite Dean with his own plate of eggs. He doesn’t miss the way Dean’s eyes flick up to Cas when he sits down, or the way Cas’s forearm brushes accidentally against Dean’s fingertips. Apparently, neither does Lucifer; he huffs a laugh from behind Sam and sits down on the countertop.

“Now what?” asks Cas quietly, and he sounds so grave that Dean puts his fork down.

“What d’you mean?” Cas glances at Lucifer.

“We have a safe house now,” he says, and raises his eyebrows questioningly when Dean doesn’t respond right away.

“So what, now we’re cooped up in here?” Dean asks, and his jaw tightens.

“You can leave whenever you want,” says Lucifer with a fluid shrug, “but the protection won’t follow you around.”

“What are we going to do about the Leviathans?” interjects Sam cautiously.

He doesn’t know how Cas feels about the Leviathan situation and he doesn’t want to do anything to upset him – not only would he feel terrible about it, he’d also most likely have Dean on his case, too. He sighs internally. His life is becoming a soap opera, and there is nothing he can do to stop it.

Dean is staring at a spot on the table.

“We’ve got a home base now.” He almost mumbles it, and Cas leans forward with a frown. “I mean, we could just– you know, wait for an opportunity to present itself.”

Silence.

Lucifer wisely doesn’t say anything; Cas’s eyes are wide. Dean sighs violently and stands from the table. Sam lunges forward to catch his chair before it falls and sprints after Dean into the library; his shoulders are tensed up and Sam reaches out hesitantly.

“Dean?” His brother turns around and there’s a conflicted mess of emotions on his face. Sam pulls his hand back.

“I’m tired, Sammy,” he says quietly, and Sam’s heart clenches. “We deserve a bit of a break. I mean, you found me again, and we’ve got Cas, and– and I just want some time.”

He looks so broken and so hopeful that there is honestly nothing else for Sam to do but smile and say yeah, he agrees, some time would be nice. The relieved slump of Dean’s shoulders is the greatest reward in the world.


	7. Chapter 7

It’s creepy, watching Lucifer constantly trail after Sam. Actually, it’s _more_ than creepy; Sam sort of does it too. After three days of lazing around in the house and not doing much more than read, watch TV, and surf the internet, Dean’s managed to pick up a lot of general _creepiness_.

The only analogy for them he can come up with is two planets orbiting the same star – it’s not really that Lucifer follows Sam around or that Sam follows Lucifer around, they’re kind of a package deal and Dean is really, honestly, trying not to let it get to him. Cas trusts Lucifer, so Dean’s going to let it slide and keep his fingers crossed that Sam knows what he’s doing.

He stops behind the couch where Cas is curled up; Sam is shrugging on his jacket a few feet away from the door.

“Anything you need from the store?” he asks.

“Pie,” says Dean automatically. Sam rolls his eyes and opens the door.

“Anything _else?_ ”

Dean shakes his head and waves him off. Lucifer is suddenly in the doorway next to Sam and he can’t bite back the comment.

“So what, are you his shadow or his stalker?”

Sam pulls a bitchface and walks out but Lucifer, to his surprise, starts laughing.

“I like you, Dean,” he says mid-chuckle. “I do.” And with that, he closes the door with a sharp snap. Dean automatically looks at Cas, eyebrows furrowed.

“Gabriel got his sense of humor from Lucifer,” Cas says by way of explanation, looking vaguely confused. His voice is more gravelly than usual and judging from how deep into the blankets he’s buried, Cas is about thirty seconds away from falling asleep.

“No wonder I don’t like either of them.”

Dean huffs a sigh and leans over the back of the couch to run a hand through Cas’s dark mess of hair and press a kiss to his temple. His stomach lurches at the thought of being so close – it’s been happening more and more often ever since Cas _kissed him_ that one morning and he can’t stop thinking about it, but he can’t bring himself to kiss him back because he’s _scared_. He knows he’s the type to go into a rapid spiral of emotional dependency and god, Cas doesn’t deserve that.

He forces himself to move to the kitchen instead of watching Cas fall asleep; Sam had insisted on buying some ‘real’ plates and cups and utensils, then he’d promptly washed them and charged Dean with putting them away _appropriately_. He sneers at nothing in particular and directs it at Sam. It’s surprisingly difficult not to just shove everything into one cabinet – he tries to remember how everything had looked back at Lisa’s house and before he knows it, nearly an hour’s passed and he’s still got the last group of cups to shove somewhere.

He pauses for a few seconds and looks out towards the living room. He can just barely see Cas’s head from where he’s standing but right then he knows something’s wrong. Cas’s shoulders are hunched and tense and he’s breathing fast and shallow; Dean bolts into the living room right as Cas jolts awake with a gasp and he’s there, kneeling next to him, one hand tight on his bicep.

“Cas,” he calls, and Cas is reaching out with a shaking hand; his eyes are wide and he looks terrified. “Hey, Cas, it’s okay.” Cas’s hand is clenched tight in Dean’s t-shirt and before he knows it he’s being pulled up onto the sofa, onto _Cas_ , and Cas is clinging to him as if his life depended on it. “What was it this time?” He murmurs it into Cas’s hair and he’s only now beginning to realize how much he likes it – messy and dark and just the slightest bit curled. Cas presses his forehead deeper into Dean’s shoulder.

“Falling,” he whispers, and Dean realizes his whole body is trembling. He pushes himself up and pulls Cas along with him.

As much as he generally doesn’t do cuddling, a) this is Cas and b) his big brother instincts are kicking in – he wraps one arm tightly around his ex-angel and rubs a slow circle in his back with the other hand, just like he used to when Sammy was a kid, letting Cas work through this by himself.

Cas’s breathing slowly evens out and with each breath his death-grip loosens. Dean is more than a little terrified by the fact that he misses the contact, the way Cas’s chest feels against his and the warm press of a body. He looks at Cas – just looks at him, takes all of him in. Dean’s hands are loose on his hips and their legs are pressing into each others’ at awkward angles and Cas is sort of twisted to the side so Dean leans forward and kisses him for no other reason than it just feels right to. It’s a little longer than the other one; Cas is a little more exploratory, a little less hesitant, and Dean is positive that someone’s set his chest on fire.

Cas obviously still hasn’t mastered the concept of personal space because he pulls back less than an inch before fixing Dean with a stare that makes his breath hitch. The rational part of his mind (or, at least, what’s left of it) is thrown into gear.

“Cas,” he murmurs, and nearly loses his train of thought because Cas is still so close that their lips barely brush together. “If, uh– you have to let me know if I do something that’s not okay.” He leans back to get a good look at him; this is serious and he hopes Cas gets it. “You know, if I– if I, uh, make you uncomfortable. Or something.”

Cas leans forward and barely, just barely, draws his mouth along Dean’s jawline. His mouth goes dry.

“I doubt that’ll happen,” he murmurs, and Dean shivers because his voice is low and rough and he really _should not be turned on_ – “but I will make sure to let you know.”

Dean exhales (it’s not a moan, it’s _not_ ) and turns his head to catch Cas’s mouth. He wonders why, exactly, they weren’t doing this years ago. Cas is a little clumsy but his eagerness more than makes up for it; he’s somehow on his back now, one hand curled tight in Cas’s hair and the other sliding slowly up the back of his shirt. He’s surprised at how natural and okay and _right_ this feels, as he licks his way into Cas’s mouth and feels hands tighten on his ribs in response. This is where he’s supposed to be, with Cas pressed in a warm line against him, breaths already getting ragged, bodies fitted perfectly against each other.

He _really_ hopes it takes Sam hours to get done with the groceries.

 

* * *

 

Sam is trying not to let this weird him out.

He’s shopping for groceries _with the Devil_ so he can go back home and help make dinner for his brother. Oh, and the angel who used to be God. A few years ago he was scrambling to stop the Apocalypse and now he’s standing in the meat section of a grocery store, trying to find something that can be turned into hamburgers. There’s a part of him feebly wondering whether this is Lucifer creating some kind of elaborate torture, but he knows that can’t be true.

He sighs and picks up something labeled 97% lean – it looks edible and it’s definitely burger-patty-shaped and it’s the last thing on their list. He heads across the store to find Lucifer.

The vessel mojo must be getting stronger, he thinks, because he always instinctively knows where Lucifer is; it’s a slight tug in his gut that leads him in the right direction. He hasn’t spent much time away from the Devil in the past month or so, so he supposes it makes sense for this _ability_ , or whatever it is, to show up now that they separate more often. It’s starting to scare him a little, the fact that he’s so used to Lucifer – it makes him uncomfortable to be separated from him, the same way it makes him uncomfortable to be separated from Dean.

By all means, it shouldn’t be that way. At all.

Dean is his flesh and blood and Sam’s _supposed_ to feel his absence, but Lucifer is the _fucking Devil_ and this whole thing is getting out of hand.

He quickly shuts out the part of his brain that’s been whispering in Lucifer’s voice.

  
  


By the time they head back to the house, it’s dusky and the shadows are long. The house is old, slightly decrepit-looking, but it’s beautiful. Sam thinks that maybe, in some parallel universe, the four of them could’ve carved out an island in the river of time – they could live a quiet life here, with food and coffee and books and each others’ company, while the world rages on around them.

As if they could ever be that lucky.

Lucifer shoots him a long look, evidently having picked up on some of that, and Sam shakes his head to dismiss the daydream. Dean is stretched out on a couch when they walk in, hands behind his head and apparently very satisfied with himself over something; Cas is browsing the cupboards and there’s a chipped mug next to the rapidly-heating tea kettle.

“Oh–” Sam suddenly remembers. “I bought green onion and soy sauce. You know, for that fried rice recipe you found?” A small, rare smile flits across Cas’s mouth.

“Thank you,” he says, as grave as ever, but there’s warmth in his words and excitement in his eyes. “It’ll make for a good side with pan-fried chicken.”

“ _Yeesh_ ,” says Lucifer from behind them, and Sam can feel him rolling his eyes. “Going to join the Sunday afternoon ladies’ club, are we?” Dean walks into the kitchen at this and rapidly turns his laugh into a cough.

“Even though you don’t need to eat, food is good,” Cas mutters under his breath. Sam wonders for half a second where Cas picked up _sass_ , of all things, and then realized that it had been, of course, Dean. Typical of him to only pass on his best traits.

The kettle whistles shrilly and Cas reaches for it, but Dean picks it up before he can put down the groceries in his hand. There’s something _there_ , something Sam can’t exactly put his finger on – the way Dean seems to intercept Cas’s trains of thought, the way there’s something different about the way Cas stares. He’s on the verge of being on the brink of maybe being able to catch a glimpse of it but there’s _something_ and it’s making the kitchen much warmer and much more _alive_ , and Sam smiles to himself.

Lucifer’s agreement on the topic hums deep in his bones.


	8. Chapter 8

Sam walks downstairs one morning to find Dean and Lucifer having an in-depth discussion about Back To The Future and the mechanics of time travel at the kitchen table, complete with a diagram scrawled on the back of a take-out receipt.

 

* * *

 

Cas’s favorite place to be is the sunroom. It’s not too big, maybe only 10 feet square, but it’s all glass and Cas can sit there for hours, surrounded by books and sunlight. He looks the most like an angel, Sam thinks, when he’s propped up against the wall, brows furrowed over some obscure passage, with Dean slumped in the corner next to him and snoring quietly, light painting both their faces.

 

* * *

 

After two weeks, they decide to check the last place they knew Frank had been. The drive takes nearly four hours; by the end, Cas is asleep in the backseat with his head lolling dangerously close to Lucifer’s shoulder. Dean’s eyes keep checking the rearview mirror much more than necessary.

The trailer is completely wrecked when they finally get there. There’s blood everywhere, drawers upended, every hard drive torn to shreds, stripped wiring littering the floor. They salvage what they can -- Lady Luck must be on their side, because under a pile of destroyed monitors is what they need to make fake IDs.

Dean also finds the keys to the Impala and an address. It’s the closest to crying of happiness that Sam’s ever seen him.

 

* * *

 

The Devil is – well, not _ranting_ , exactly, but on a prolonged spiel about the creation of the universe and about how petty and puny human astrophysicists are. Sam would find this fascinating at any other time than ass o’clock at night.

“Lucifer,” says Sam tiredly, almost pleadingly, “Luce, c’m _on_.”

He stops talking at the nickname and the corners of his mouth quirk up. Sam looks up from his seat on the edge of the bed and gives him his very best puppy-dog face, the one that always makes Dean purse his lips and give in. Lucifer sighs and walks forward to where Sam’s sitting, right into his personal space; one hand pushes slowly through his hair as Sam leans into Lucifer’s stomach and breathes in the blizzard-thunderstorm-cold-rain smell that’s been home for years now.

“You humans and your sleep,” says Lucifer, teasing and light and fond. Sam is way too tired to be actually thinking about implications – he tugs Lucifer so he falls forward, rolls them both over, cradles the back of his head, tucks him under his chin, drapes an arm around his back. All he knows that this is safe and it’s good, to be around this otherness-archangel-devil-creature whose soul is supposed to be his perfect match.

 

* * *

 

“You’re not just my vessel, Sam,” murmurs Lucifer one night, mouth against Sam’s temple and a hand carding loosely through his hair. “I’m a part of you. Always have been, always will be.”

Sam doesn’t know what to make of the lurch in his stomach or the blazing hum in his bones.

 

* * *

 

Lucifer is bright and cold and _alone_ – there’s a terrifying emptiness there and Sam feels an overwhelming urge-need to fill that space, to fit himself in with Lucifer because he knows that Sam-shaped hole is where he belongs, because he’s got a Lucifer-shaped hole in his chest, because it’s right and good and safe and nice.


	9. Chapter 9

Sam knows he’s practically bursting with excitement as he slams the newspaper down onto the kitchen table.

“Two towns over,” he says, jabbing at one of the things he’s circled. “Three deaths by drowning in the same high school locker room. You _know_ this is our kinda thing.” He’s brimming with energy – it’s a way out, they can stretch their legs, they’ve been way too cooped up, and Sam never thought he’d be the one raring for a hunt but here he is. Dean automatically picks up the paper and squints at it, then sighs and sets it down.

“Sounds like us, yeah,” he says.

Cas pulls it out from under his hand and skims it too. There’s a spark in his eyes when he folds it up and looks at Sam.

“So?” he says, and there’s an undercurrent of excitement that’s matching Sam’s. He looks at his brother and falters. There’s something off and closed about his face, something tight and drawn about the way his eyes flick to Cas.

“We’ve been out of the game for a while, Sam,” he says. “I’m all for saving people, but–”

“But what?” Sam’s impatient, he wants to _go_ , he wants to ice something to get rid of the restlessness that’s been building up in his chest.

“Dean, people have been hurt,” says Cas, and Sam gives him points for diplomacy. “We should make sure whatever it is doesn’t hurt even more people.”

“My heart is bleeding,” says Lucifer disinterestedly from the corner.

Sam scowls at him; he winks back.

“You’re human,” Dean mutters quietly, looking neither Sam nor Cas in the eye. “And after–”

He stops abruptly, shakes his head and makes a quiet, angry noise.

_Ah_.

So that’s what it is. Sam recognizes it for protectiveness, now – he knows the way Dean’s fingers drum anxiously on the tabletop, the way he’s fidgeting.

“I’m not helpless,” Cas fires back, indignant.

“I’ll stay here with Cas,” says Dean loudly and he’s all stubbornness – Sam can already tell that this is _not_ going to end well.

“I want to go,” says Cas, and it’s low and dangerous and threatening. He tops it off with a bitchface that puts Sam’s own to shame. “You have no right to control me.”

“No,” snaps Dean, and Sam slowly pushes his chair away from the table.

He knows his brother well enough to know that’s the You’re Too Young To Hunt voice (or, in Cas’s case, Too Newly Human) and yeah, this is going to end very badly. Lucifer is already edging out of the kitchen but Cas and Dean are too busy arguing to care. Sam’s in the doorway as Cas starts to raise his voice.

“I was an angel, Dean,” he snarls, “I can take care of myself. You know that.”

He doesn’t catch Dean’s response but he can hear a hand slamming on the table as he sprints silently up the stairs. He manages to get halfway to the second floor when Dean’s roar rips through the entire house.

_“Because I care about you!”_

The silence is deafening.

Two things have Sam floored.

One, his brain has been conditioned throughout childhood to lock up when Dean’s voice goes loud and harsh and _scared_ like that, and two, _what_. He’s frantically trying to wrap his head around the fact that Dean actually explicitly said something to do with feelings, without threats or coercion or booze.

It’s not weird that Dean cares about Cas – that’s obvious, it’s been obvious for years that Cas is family, that Cas loves them and they love Cas – it’s that Dean is showing a side of himself that _Sam’s_ rarely seen. Sam also very suddenly realizes that he does _not_ want to hear the rest of this conversation (this is Dean’s, it’s all Dean’s) so he sprints up the rest of the stairs as quietly as he can and sinks down onto his now-a-mattress-on-top-of-some-wood bed and opens one of Bobby’s old books. He can barely hear anything coming from the kitchen any more (at least they’re not yelling) but it’s still hard to concentrate on reading the text.

“I feel obligated to give Dean the big brother speech,” says Lucifer mildly. Sam’s long been used to the way Lucifer mojoes himself into his-their room regardless of a closed door, so much so that he doesn’t even bat an eyelash at his sudden appearance. Lucifer is tracing over his knuckles with light, cool fingers, and after a couple of seconds Sam relaxes into the touch.

“The what?” Lucifer grins.

“You know,” he continues airily, “the whole ‘if you bad-touch my little brother I’ll kill you’ speech.”

“Are you– Christ, I don’t want to think about that,” groans Sam. Lucifer just chuckles quietly in response; his fingers are resting on the inside of Sam’s wrist, right on his pulse, and he abandons the pretense of the book in favor of turning his hand over and letting Lucifer explore his palm. He sighs. “Dean can be such an idiot sometimes,” he says, frustration evident, “and this is something he _can’t_ be an idiot about.”

“You care about Castiel,” says Lucifer, and it’s not a question.

“Cas is family,” replies Sam simply.

He can only hope that Dean’s not introducing him to the Winchester brand of dangerous codependency.

 

 

When Sam trudges downstairs the next morning at the crack of dawn – quite literally, as the sun is _just_ starting to show – he finds Cas already starting on some coffee.

“Hey, Cas,” he mumbles, then fishes a mug out of the cabinet and nearly spills coffee on the countertop as he fills it.

“Good morning, Sam,” he says, sounding as if he’d had the most restful night of sleep ever.

“Did you, uh, figure something out with Dean?” The coffee burns hot and bitter and perfect down his throat; he downs half the mug in one go.

“We’ve resolved our differences, yes,” he replies, piano fingers curled perfectly around his own mug. “Dean has accepted the fact that I can, indeed, take care of myself.”

“Good for you, baby bro,” says Lucifer from the doorway.

“Good morning, Lucifer.”

Sam notes that it’s a little more strained than the ‘good morning’ he got; he knows Cas is still nervous about having Lucifer around. He couldn’t possibly imagine how it would feel to have your Legendary Number One Bad Guy older brother living under the same roof. They get along, at least – it takes Cas less and less time to be coaxed into easiness around him, and Sam’s glad that Lucifer doesn’t actually screw with Cas the way he’ll screw with Dean.

And, speak of the devil – Sam immediately regrets his internal monologue’s choice of words – he can hear heavy footsteps on the stairs. Dean barrels into the kitchen and doesn’t say a word until he’s taken a long draught of coffee.

“So,” he says, wiping his mouth with the back of his hand, “let’s get this thing.”

 

 

It turns out to have been the nasty-ass ghost of an ex-principal, ectoplasm and everything – Sam was unpleasantly reminded of the last time they’d found a spirit that pissed, but at least this time there was nothing personal.

Cas has a cut on his forearm and busted knuckles, from an impressive right hook to a possessed janitor. Sam can feel a bruise forming on his hip; he and Dean are relatively unscathed, just the usual scuffs and scratches.

He keeps catching Dean glancing into the rearview mirror, both at Cas _and_ Lucifer. Gratitude swells in his chest. He thinks Dean might finally be coming around to the fact that Lucifer isn’t here to kill any of them – he’d yanked Sam out of the way of a heavy, falling bookshelf right in front of Dean and without Lucifer, Sam would have definitely ended up in the hospital. Or worse. There’s (grudging) respect in Dean’s eyes when he flicks them up to the rearview mirror, and Sam smiles to himself.

Warm contentment from Lucifer curls in his bones.

 

 

Dean ushers Cas into the kitchen with the first aid kit the second they get home.

_Home_.

Sam revels at the novelty of being able to use that word – a place to come _home_ to, a place where he has _his_ bed and _his_ room and _his_ toothbrush in _their_ bathroom and food in _their_ kitchen.

It’s past midnight but he takes a long shower anyways, letting the hot water work through all of the muscles he thinks he pulled, making sure there’s no grave dirt stuck under his fingernails, rubbing grit out of his eyes. There’s still soft light coming from the kitchen when he’s out so he assumes Cas and Dean are still down there – probably drinking a beer, knowing Dean.

Lucifer is in boxers and a t-shirt, idly adding to one of the sigils on the wall. It nags at Sam for a second, how utterly fucking _bewildering_ this is. It hadn’t seemed so weird a couple months ago, telling Lucifer that jeans are really uncomfortable to even sleep _with_ , nevermind _in_ , or telling Lucifer that he likes the feeling of his hair being played with because Jess used to always do it, or telling Lucifer that he likes his company. It’s weird now, when it hits him how domestic this is, that Cas and Dean are downstairs in _their_ kitchen having a beer and he’s going to sleep in _his_ bed with _his_ –

Yeah, not going to finish that train of thought.

“You’re not hurt, right?” asks Lucifer idly as Sam drapes his towel over the back of a chair and paws absently at his still-wet hair, trying to get it so that it won’t get tangled in the morning.

“Nope,” he answers, halfway through a yawn, and tumbles into the bed. His bed, in his house, with his pillows. It’s a beautiful thought. The covers might be a little scratchy and the mattress a little lumpy, but it’s still a thousand times better than any motel. Especially when Lucifer slides in behind him and loops an arm around his chest and buries his face a little too intimately into the back of his neck.

“Good,” he murmurs, and his breath is warm against Sam’s skin. “It’s bad enough that Castiel got hurt, when he should be above stupid _human_ things like that.”

“Being hurt is part of being human,” says Sam stubbornly, even though it’s neither intelligent nor a comeback. “Humans are flawed and dumb and rough and broken and violent, but we hurt and we feel and we try our best to be good because of it.” Lucifer is silent, so Sam plows on. “But really, you guys aren’t that different from us. All of the dicks we met were greedy and violent. Angels are just as _bad_ as humans.”

“Maybe we learned from you.”

Lucifer’s voice is quiet and subdued and for some reason, the admission feels monumental. Sam is inexplicably overwhelmed; he turns around and wraps himself around the Devil, tucks his head under his chin and lets dirty-blonde hair itch at his nose. He doesn’t want to see the look on Lucifer’s borrowed face, not when there’s so much conflict and doubt and _defeat_ whirling in that one dimension they share.


	10. Chapter 10

Sam is making scrambled eggs when it hits him – they’ve been here for three months. To the day, he thinks, and nearly drops the pan as he’s trying to scoop the eggs onto a plate.

“Watch out, Gordon Ramsey,” mutters Lucifer absently, not bothering to look up from the newspaper. He’s got Politics and Cas has Arts & Entertainment, and the comics are set aside for whenever Dean decides he wants to wake up. The domestic-ness somehow managed to turn into normal-ness, which descended into comfort and routine. There’s thunder on the stairs and Sam rolls his eyes; Dean is only ever capable of _not_ walking like an elephant while on a hunt.

“Morning to you too, Dean,” Sam grouses as a good chunk of his eggs end up on a piece of toast in his brother’s hand. Dean smiles at him like a toddler, mouth full of food. “ _Gross_.”

Sam reaches for a fork and out of the corner of his eye, he thinks he might have seen Dean ruffling Cas’s hair with a mumbled-though-food ‘morning.’ A flicker of amusement from Lucifer confirms it and he’s left wondering for what feels like the hundredth time this week whether anything’s going on between his brother and their ex-angel. Lucifer is a flurry of thoughts – Dean’s little smiles, the way Cas stares, normal touches that last a little too long – and Sam shakes it off. He really, _really_ doesn’t need to think about the possibility of his brother _doing things_ , especially when Cas is involved because to him, they’re both family and that’s frankly disturbing. He doesn’t want to ruin his appetite, especially halfway through breakfast. Lucifer chuckles out loud.

“Time for coffee, Sammy,” he says, stretching languidly.

“Let me eat, Christ,” mutters Sam.

Oh yeah, they’re a real cheery bunch in the mornings.

 

* * *

 

He doesn’t know when coffee became _their thing_ , but it did, and Sam still mostly refuses to call it ‘their thing’ in his head. It started when Sam’s solo coffee runs turned into ‘Sammy bring me a coffee’ and ‘Sam, would you mind getting a coffee for me as well?’ and he’d needed some extra hands to haul it all back.

Marie-the-barista grins cheekily and waves when he and Lucifer walk in; she’s already scribbled names on four paper cups by the time they reach the counter. There’s a decent crowd at Cat’s Cradle today – the usual mix of college kids with laptops and businesspeople grabbing a quick dose of caffeine.

“Two coffees black, and what’s for you and Cas today?” she asks Lucifer, still grinning ear-to-ear.

Sam likes that about her, that she’s all cheerfulness and smiles and curiosity and that she’s a total motormouth. She’s a good handful of years younger than him and he likes talking to her mostly because sometimes he really misses college life, misses the energy and the community.

“Caramel macchiato and a, uh–” Lucifer frowns for a second and Sam scrambles to remember for him what it was that Cas had wanted to try. “–dirty Chai latte,” he finishes. Marie scrawls on their cups and rings them up.

“$10.24’s your total,” she chirps, and Sam fishes for his wallet. “Dude, so my religious studies class is really awesome.”

“Yeah?” says Sam, grinning right back at her. Deep-seated amusement bubbles through Lucifer and he gets that shit-eating smile on his face and it takes _everything_ Sam has not to elbow him. “I never took any of those.”

“It’s crazy!” she says animatedly, pumping at least five extra shots of caramel in the cup labeled ‘Luc.’ “We were talking about Satan in class yesterday–” Sam nearly drops his wallet. “–and I dunno, it’s crazy stuff. I mean, how the hell is he a bad guy? He basically tries to do the, like, whole free-will thing, and gets _grounded_ for it.”

Lucifer is grinning like a Cheshire cat and Sam really, _really_ hopes it’s not going straight to his ego.

It probably is.

Marie rambles right on. “ _And_ he punishes evil people. Like, that’s his job. To make sure that horrible people get punished. I mean, come _on_.” She hands the two black coffees over to Sam; Lucifer leans his elbows on the bar.

“You know, my full name is Lucifer,” he says casually.

Sam would be running a hand down his face if he wasn’t holding coffee. Marie’s eyes go perfectly round.

“No way,” she says, as if her grave refusal to accept it is final. Her hand is frozen, half-outstretched with Cas’s Chai whatever.

“Yep,” says Lucifer, and pulls the – does it count as coffee? – out of her hand.

“That is _awesome_ ,” she says, staring at him in a way that reminds Sam uncomfortably of Becky.

“Yeah, well, he definitely has me convinced that he’s the Devil,” Sam butts in.

Which, well, true no matter how you look at it.

 

 

They take a detour on their way back, braving an extra ten minutes’ walk in the cold to one of the local bookstores that sells out-of-print books. Sam’s found a couple helpful lore books and some cool first-edition classic novels there before, so it’s always worth a look. They browse long enough for Sam to finish his own coffee (Lucifer finished his in nearly one swallow and hell, Dean and Cas can use the microwave if they really want to) and head back, bookless.

Sam really likes this. He _really_ does. He knows he’s always been more eager to have a ‘normal’ life but part of why he likes this so much is because Dean is _happy_. Their sparse hunts keep his restlessness satisfied, and it’s clear that living with Sam and Cas (and Lucifer) is working out for him way better than living with Lisa had. Sam would probably be completely happy living out the rest of his life like this, except for the lingering nag of the Leviathans. Dean still stiffens whenever Dick Roman’s name comes up on TV or in the newspaper and he still spends hours on the internet, trying to dig up whatever he can. They haven’t made much headway in either finding out how to kill them or what they’re doing, so in the meantime they just _live_.

As much as he likes this, there’s a big part of him waiting for the other shoe to drop.

And it does.

Precisely three feet before they turn the corner onto their street.

 

Lucifer stops suddenly and grabs Sam’s jacket, hauling him backwards in a rare display of his inhuman strength.

“Crowley’s waiting on the front steps,” he says, and it’s a mark of his surprise that there’s no venom or humor in his voice. Sam nearly drops Dean’s coffee.

“What?”

“Crowley, jackass,” snaps Lucifer. “It never occurred to you that he could be after Castiel?”

Sam feels faint. if Crowley’s looking for Cas and Cas is with Dean–

“Can you– I don’t know, go warn them or something? Without Crowley knowing?” He runs a nervous hand through his hair, every nerve already dancing on edge. “There’s a Devil’s trap somewhere in the house, right? And–”

“Stop babbling and give me that,” says Lucifer impatiently, then yanks the coffee out of Sam’s hand and disappears.

Sam is trying hard not to freak out. He’s got a knife but it’s not Ruby’s knife and he’s got a flask of holy water, but that’s about it. He takes a deep breath and rounds the corner and yeah, there’s someone in a black suit standing on the very edge of the sidewalk by their house. He gets a couple of flashes from Lucifer – Dean scrambling out from under the Impala, Cas loading a handgun – and walks forward.

“Hello, moose,” says Crowley once he’s within earshot, as dry as ever. “Do you have any idea how difficult you and your brother are to track down?”

At that moment the door slams open and Dean’s there – Sam exhales silently.

“What the hell are you doing here?” he asks flatly.

“Rude,” replies Crowley, eyes narrowing. “I heard some gossip about our oozey mutual acquaintances you might like to hear.” A look of surprise crosses Dean’s face; he glances quickly at Sam, then looks behind him into the house. Either Lucifer or Cas must have motioned something because Dean nods and opens his hands, showing the lack of weapons.

“Okay,” he says, “get inside. We don’t want anything to overhear.”

“I noticed,” says Crowley blithely. “I have no idea how you managed to completely disappear, but–” He crosses the doorway and stops dead. “For _god’s sake_!”

Sam quickly shuts the door behind him because even if nothing supernatural can hear them now, the neighbors will sure as hell hear yelling.

“Let me out,” snaps Crowley.

“Can’t do that, kid,” says Lucifer cheerfully, and walks in from the kitchen. A devil’s trap flares into sight when he snaps his fingers. Sam’s never seen a demon go this pale; Crowley practically _withers_ at the sight of Lucifer standing before him.

“How–”

“Never mind how,” cuts in Dean. “You know something about the Leviathans?”

Crowley is still staring, somewhere between terrified and disbelieving; Lucifer is completely relaxed, hands in his pockets and with an easy smile on his face, but there’s a vastness that fill the entire room. Sam feels it like spreading wings, a practically tangible show of animalistic dominance to which the new King of Hell instantly defers. Dean raises his voice:

“ _Crowley_!”

He looks back at Dean and manages to compose himself.

“I was hoping to have a civil conversation about this, but apparently you lot never evolved past being barbarians.” Lucifer rolls his eyes. “In any case, I do have some information you might like.” He savors the pause, looking between Dean and Sam. “I know what they’re up to.”

“And?” says Lucifer, obviously having zero patience for Crowley’s power play.

“All that land that Dick Roman is buying out? All those hospitals?”

He spares Lucifer the smallest of intimidated glances; Sam nods.

“What about them?”

“He’s also bought out some medical and pharmaceutical companies,” Crowley continues. “Among them, Niveus Pharmaceuticals.”

His statement is greeted with three blank faces. And then–

“Shit,” comes a low voice. Sam glances behind him; Cas is sitting on the bottom of the stairs, with a look of terrible, dawning comprehension on his face.

“Oh, it’s you,” says Crowley, looking mildly surprised. “Figures you’re the only one with the brains to remember.” He looks back at Sam. “Niveus Pharmaceuticals? Apocalypse? Pestilence?”

“Shit,” echoes Dean loudly. “They’re going to let Croatoan loose again?” Even Lucifer looks taken aback.

“They’re going to do the Horsemen one better,” Crowley adds. “All those hospitals and medical research centers, they’re tweaking the virus.”

“What for?” asks Cas from the stairs.

“For us,” says Crowley. “Demons. Shifters. Vampires. Everything else they can eat. Imagine it – complete chaos, and no one’s going to notice people disappearing. They’ll have all the food they ever wanted.”

“Jesus Christ,” breathes Sam.

It feels like he’s been hit with a sack of bricks, then run over by a train. This can’t be happening. Not again. They stopped everything before, the world was saved, everything was okay, and now this _can’t be happening_.

“How long?” Dean manages to say, voice tight.

“Until the world’s a horde of mindless zombies? No idea,” says Crowley. “All I know is that the Leviathans are taking their sweet time. Now let me out.” Sam steps forward numbly and scratches away part of the circle. Crowley exhales and heads straight for the kitchen, finding a glass and a bottle of whiskey in record time.

“So? Now what?” Dean’s quickly making the shift from shocked to angry; Cas stands up to follow them into the kitchen.

“I’ve got people watching Roman Enterprises, of course,” Crowley says, takes a drink, then makes a face. “This is _mud_.”

Dean opens his mouth angrily and Sam cuts him off.

“So you’ll let us know if something happens?”

“God knows how, but I will,” mutters Crowley. “In the meantime, though, you should probably figure out something to do.”

“We’ve tried,” says Cas, and he sounds tired. “There’s frustratingly little lore on the Leviathans.”

“I’ve got a, uh– a _contact_ in London,” replies Crowley, shifting his weight and refusing to look any of them in his eyes. Lucifer looks sharply at him. “He might know something.”

Lucifer makes a quiet noise in his throat; Crowley manages to look both embarrassed and indignant. Sam’s wondering just what the hell is going on, because Lucifer is practically _bursting_ with mirth and he’s got no idea what’s so funny.

“Give him a warm hello,” he says in a tone that Sam instantly recognizes as the one he uses to screw with people. He’s still got no idea what’s going on, but Crowley getting ribbed for anything is fine by him.

“Yes, well–” Crowley levels one last glare at Sam and Dean. “Whatever you decide to do, do it quickly.”

And with that he’s gone.


	11. Chapter 11

Cas slumps into a chair.

“Croatoan,” he mumbles, “of all things.”

“Cas,” Dean starts, but Cas gives him a terrifying look.

“Don’t tell me this isn’t my fault,” he snarls, and Sam is currently having a hard time believing Cas is human because that voice and that look are 100% pissed-off angel.

“I wasn’t going to,” snaps Dean, and Sam has to give him points for being at least slightly diplomatic and not yelling outright. “I was gonna say you’re not going to do much good sitting there and beating yourself up.” A funny look crosses Cas’s face, one Sam’s never really seen before.

“He’s right,” says Lucifer, not unkindly. “this is your mess and you’ve got to clean it up. Moping’s not gonna help.”

Sam almost smiles. Lucifer’s only had a handful of real big brotherish moments, but they’re heartwarming for all their rarity. Sam puts a hand on Cas’s shoulder.

“This might be _your_ mess but it’s _our_ problem, too,” he reminds him. “It’s personal for us. This isn’t just your burden. I mean hell, if you want to blame something, blame destiny for trying to screw with our lives. That’s what this all boils down to, isn’t it?” All three of them are looking at him now. Sam swallows uncomfortably. “You know. If we hadn’t started the Apocalypse then we wouldn’t have had to fight against it, and the whole Angel Civil War wouldn’t have happened–”

“Sam,” says Cas, in one of his rare interruptions. “I do appreciate your mentality, but what I did was my choice, and I chose the wrong thing. I can only be glad that I have you to support me. _All_ of you.” Cas looks pointedly at Lucifer with that, and Sam feels a flicker of surprised happiness from him.

“‘Course you’ve got us, Cas,” Dean says, and claps him on the shoulder. He’s got one of his really rare smiles on, and Sam wonders for the millionth time what exactly made Dean go from blaming everything on Cas to standing by his side. He’s not going to push it, since it’s personal and god knows Dean’s allergic to feelings.

“I guess I’ll... take another look at the Bible,” says Sam. Cas is looking at Dean with that _something_ in his face and whatever it is, it’s making the entire room awkward.

 

* * *

 

Evidently, Bobby had been able to read the Hebrew in one of the hundreds of Bibles he left behind. Sam sure as hell _can’t_. At least not yet. One of the first things he’d done was to sit down with Lucifer, the Hebrew Book of Job, an English translation, and a pen and paper. It’d turned out that neither the original nor any translation said anything about how to kill them (or that they could be killed at all) so they’d labeled it as a lost cause.

And evidently, Lucifer has an issue with using chairs the way they were intended to be used. It’s one of Sam’s minor pet peeves and it sets his teeth on edge for no good reason when he _perches_ like that.

“You won’t find anything in there,” he says, and shoots the Bible a skeptical look. “Nothing of use, anyway.”

“So what, I’m supposed to sit around and do nothing?” snaps Sam. The Devil just shrugs and hands him a book.

 

* * *

 

He’s pretty sure Cas hasn’t slept since Crowley’s visit. There are dark circles under his eyes and he looks paler than usual; he’s been holed up in the library for days on end. Sam hopes he’s at least eaten something.

 

* * *

 

Dean spends a surprising amount of time around Lucifer, asking him to double-check facts or check translations. It’s heartening to see them getting along, one way or another.

 

* * *

 

After three days, Dean and Sam run into one of Crowley’s demons while on a midnight coffee run at a gas station.

Nothing. One big, fat nothing.

Nothing significant going on at Roman Enterprises, nothing from Crowley’s contact, _nothing_.

 

* * *

 

Sam can almost taste the desperation in the house by the time a week passes. They check the news constantly, keeping up with every single move Dick Roman makes. There is absolutely _nothing_ to be found; they can hardly take on an army of Leviathans, just the four of them, and even all the hunters they can muster wouldn’t be enough.

 

* * *

 

Something’s happening.

Sam feels it like the sharp snap of an epiphany and walks quickly downstairs, tugging a shirt over his head, and he nearly runs into Lucifer as he’s walking out of the library and into the living room. Lucifer looks at him briefly.

“Castiel,” he says, and Cas’s dark head turns from the sofa. Lucifer says something in Enochian, then– “That would work. We could use that.”

Cas stands up so fast that he dumps all of the books in his lap onto the floor; Dean looks over from the kitchen at the noise, brows furrowed.

“Yes,” says Cas, without a trace of doubt in his voice. “I can do it.” Sam has no clue what’s going on but he can tell it’s deadly serious.

“No,” says Lucifer, “you _can’t_. Not as a human.”

“What the hell is going on?” barks Dean, sparking with anger already. There’s a rolling cloud of tumultuous emotions roiling in Lucifer and Sam doesn’t have the patience to sort them out, not now when something is _happening_.

“There’s a spell,” says Cas, focused and sharp. “It hasn’t been used since–” He glances at Lucifer, who shrugs. “–for eons. It binds a creature – all of its iterations – and then uses the life of anyone working the spell in order to make them cease existing. It’s not a death spell,” he clarifies. “It’s the cessation of existence. An ultimate end.”

Sam processes this for a few seconds and then Dean _gets it_.

“No,” he says loudly, “Cas, no, you _can’t do this_ –”

“This is my mess, Dean!” Cas snarls back. “It’s the least I can do, to donate myself to end this.”

Dean whirls on Lucifer.

“You are _not_ including him in this.”

“He’ll do what he wants,” says Lucifer icily, “and if he wants to die in order to save this planet, then so be it. I might remind you that an _angel_ has to cast this spell, Dean. There’s only one of those in this room. Besides, the more sacrificial lambs we’ve got, the better.”

Sam unglues his tongue from the roof of his mouth.

“Hold on,” he interrupts, “you can’t seriously be thinking of rounding people up and slaughtering them like cattle for this.”

“ _Voluntary_ sacrifices, Sam,” says Lucifer impatiently.

The room is silent for ten seconds, fifteen, thirty, then–

“I’m in.”

Sam surprises himself by saying it. It’s the right thing to do, just like it was the right thing to jump into the Cage. It’s something he has to do, he just _knows_. The look Dean gives him hurts more than anything he’s felt in a long time.

“Sam,” he says weakly, “you can’t–”

“Yes, I can, Dean,” he replies gently. “How many times have we died and come back? How many times have we done it to save people? This is– you know. Bobby’s gone. Dad’s gone. Ellen and Jo and Ash, they’re all gone. As far as hunters are concerned, we’re nearing the end of the line, too.”

And god fucking _damn_ it, Dean looks like he’s on the verge of tears.

“Dean,” says Cas quietly, “you don’t have to do anything you don’t want to do. Don’t let our choices influence yours.”

“Yeah?” Dean’s knuckles are white. “How the hell does that work, huh? Everything I care about, wiped away, and me left behind? What kind of a choice is that?”

Sam puts a hand on Dean’s shoulder and tries to swallow around the lump in his throat. Another minute passes in complete silence, and then Dean sighs.

“You’re right.” Sam can feel him sagging under his hand. “Damn it, you’re right. This– I’m tired, I really am.” His eyes are suspiciously bright, and he’s refusing to look either Sam or Cas in the eye. “Better a bang than a whimper, right?”

Cas moves forward and gently wraps a hand around Dean’s bicep; Sam senses that there’s An Impending Moment and slowly backs away. Lucifer is looking at him and his eyes are full of something great and terrible and sad. His heart twists.

“Sam,” calls Lucifer; his voice is soft but there’s an undercurrent of seriousness that’s making Sam shiver. He follows Lucifer into the library, out of earshot of Dean or Cas. There’s turmoil in his gut and he can’t sort out anything, he’s still reeling and blank and shocked over what the spell would entail, mind being pulled in about seven thousand different directions but his attention snaps straight to Lucifer when he feels a cool hand on the side of his neck.

“Sam, you need to understand that I can’t do this without you,” Lucifer whispers, sounding older than Sam’s ever heard him. “This is a sacrifice I’m willing to make but I cannot do anything without your agreement. We’re bound.” Sam swallows when the immensity of it hits him – that this isn’t something that either of them can do, this is something they have to do _together_.

“This is mine and Dean’s business, first and foremost,” replies Sam. “I mean, if anything, I’m dragging you into this. I–” He pauses, swallows thickly. “I wouldn’t be able to go through with this unless I knew for sure I’d end up either with you or with Dean.”

He knows he sounds desperate but he can’t help it; he sounds like every single person must sound to a Reaper, asking what’s on the other side, fooling themselves into believing they’ll get a straight answer.

“I can’t make any promises,” says Lucifer, and Sam’s nearly drowning in his unspoken apology. “Either you and I end up in the Cage or you get sent upstairs. One or the other. The spell’s not going to take us with it.” Sam exhales shakily; his knees feel weak with relief.

“I can’t do this without you either,” says Sam. “You and Dean and Cas.” He feels like a little kid, meek and scared and small.

“I know, Sam,” murmurs Lucifer, and pulls Sam’s forehead down to rest against his. “I know.”

 

* * *

 

Cas falls asleep watching Star Wars that night.

Dean forgives him – it’s Attack of the Clones and he’s got half a mind to turn it off, but it’s about to get to one of its few redeeming parts, so he pulls a blanket over both of them and absently combs a hand through Cas’s hair. He’s curled loosely into Dean’s side, one hand resting on his stomach with a couple of fingers just barely tucked under the hem of his t-shirt; his soft, slow breaths leave a trail of goosebumps down Dean’s neck.

He can’t help but reflect on how much of an exception to every goddamn rule Cas is. It drives him crazy sometimes, the way his heart stops or stutters at the tiniest things Cas does, but it all boils down to the fact that at this point, he could live without Cas about as functionally as he could live without Sam. It’s scary and new and he doesn’t like to think about it but at times like these, when he presses a kiss into Cas’s hairline, everything feels okay.

“Uh–”

Dean starts and whips his head around to see Sam at the foot of the stairs, doe-eyed.

“We are _not_ going to talk about this,” he hisses fiercely, because knowing Sam it’ll dissolve into Feelings and Why Didn’t You Let Me Knows and How Longs and that’s the last fucking thing he wants. Sam still has that utterly weirded out look on his face when he puts his hands up in defeat.

“Just– don’t be dumb,” Sam whispers back, and shuffles awkwardly into the library.

Dean huffs and pulls Cas closer to him, resolutely ignoring the low voices in the other room and concentrating instead on Star Wars. Even if it _is_ Attack of the Clones.

Cas wakes up just in time for the fight against Dooku, even though he spends most of it with his head buried in Dean’s neck, half-draped across his stomach. He turns off the tv when the marriage scene comes on and makes a quiet noise of disgust; Cas sits up and yawns, then lies down with his head on the other side of the couch. Dean does a quick check behind him – the light’s still on in the library and Sam and Lucifer are talking – then leans over Cas and kisses him once, twice.

“Come on,” he murmurs, mouth lingering on his jaw, “bedtime.”

Cas looks at him with those stupid endless eyes of his and Dean’s struck for the thousandth time with wonder at how a creature like this could possibly want to be around someone like him. He eventually gets Cas to stand (even though he resolutely keeps the blanket wrapped around his shoulders) and watches him walk heavily upstairs.

He takes a deep breath and walks towards the library. Sam and Lucifer are hunched over some old, thick book; Sam’s got a pen in one hand and Lucifer is dictating something too quietly for Dean to hear. He leans against the doorframe and clears his throat. They look up at the same time.

“Sam, uh–” He pauses for a good few seconds, completely lost as to what to say, never mind _how_ to say it. “With.... that. The _stuff_. Um, yeah, not–”

He makes an oblique gesture with his hands, trying and failing to encompass Cas and himself and them and whatever it is that’s going on, the thing that has no name. Sam stares at him, and the steel bands around his chest loosen when the corners of his mouth turn up into a familiar, quiet smile.

“Don’t hurt yourself, Dean,” he teases softly.

“Whatever.”

“You two are _so_ articulate.”

He catches Lucifer’s dry comment as he heads up the stairs after Cas, and resists the urge to walk back and flip him off.


	12. Chapter 12

Sam looks up the second Dean walks into the library, cup of morning coffee in one hand. He looks resigned and Sam feels a tiny bubble of hope forming because, however fucked up it might be, better the devil you know (ironically, the idiomatic ‘devil’ being Heaven), and better to go out with a bang than a whimper.

“So,” he says quietly, “your... thing. What’s it going to take?” He addresses Lucifer and Sam watches them both, his brother and his– friend? Possessor? Tormentor? _Soulmate?_

Lucifer crosses his arms.

“Well, for one thing, we’ll need to catch and bleed one of those things,” he replies, and Sam is _so_ fucking grateful that Lucifer isn’t being snarky or condescending. He’s all business.

“And?” prompts Sam. Lucifer sighs and runs a hand through his hair, making it stick up even more than usual.

“This is where it gets problematic,” he says, slight frustration bleeding into his words. “We’ll need an area large enough for the spell, which is going to be no easy task considering you _ants_ are crawling all over the globe.”

“How big are we talkin’?” Dean says, and Sam can see the cogs turning.

“As big as possible.” Dean looks at Sam and the lightbulb is practically blinding as it goes off in Dean's head.

“As big as, like, southern Wyoming?”

_Ding ding ding._

“Colt’s railroad!” blurts out Sam excitedly, and scrambles through the mess of paper on the desk to find a map. Lucifer is looking at both of them like they’re speaking another language. “Luce, look– Samuel Colt built a railroad in southern Wyoming–” Dean walks over and grabs a pen too, and together they mark out the five old churches. Sam connects them. “–and it makes a huge Devil’s Trap surrounding a Devil’s Gate. Pure iron.”

“You know, I’m so tired of you people blaming everything on me,” grouses Lucifer. “Devil’s this, devil’s that, come _on_.”

“Dammit,” says Dean suddenly. Sam look at him for an explanation. “Azazel must have broken it somewhere to walk in.”

Lucifer looks closely at the map.

“I’ll be able to fix it,” he says. “Good call, though. This’ll work fine.” He taps the map. “I’ll need some of their blood to lay down the spellwork, though.”

“Dean and I can take care of that,” says Cas from the doorway, hair wet and mussed from the shower.

Sam is pleasantly shocked when Dean nods in agreement. Dean hasn’t blown up over Cas hunting since that first time, but it’s still obvious how worried he is every single time they go out to track something down. His brother might actually be learning to trust someone, he thinks with deep-seated amusement.

“Trust? Oh, _please_ , are you blind?” Lucifer snorts back, though his own amusement is humming deep in Sam’s core.

“What?” Dean blinks in confusion at the non-sequitur and Sam laughs.

“Nothing, never mind,” he says. “Are you guys sure you can handle it? Leviathans don’t usually do the solo thing.”

Dean shrugs.

“We’ll figure out a way to get one of ‘em on their own.”

 

* * *

 

It’s a quiet few days without Dean and Cas. Lucifer spends the majority of his time drawing up the spell and tweaking it, drawing circles over and over and scrawling Enochian in the borders, looking at different patterns and layouts and measurements. Sam feels utterly useless – he knows nothing about Fancy Angel Spells so he can’t help Lucifer, and he can hardly send himself to wherever Dean and Cas are at the moment. It’s a little pacifying that he’s not completely panicked, being away from his brother. He’s got a sneaky suspicion it has to do with the fact that neither of them are really alone, that he’s got Lucifer and Dean’s got Cas with him.

Sam manages to pull the Devil away from his work a couple of times a day, for a coffee run or to get groceries or company during dinner or for an impromptu Terminator marathon. He alternates between the library and the sunroom (sometimes the kitchen) and Lucifer inevitably finds him, bringing along his piles of paper and pens and ruler and compass and protractor and god knows what else. The silence is always companionable and warm, filled with paper rustling or the click of Sam’s keyboard.

Sam’s startled out of a nap when his phone rings; he raises his head and stops fucking _dead_ for a couple of heartbeats because he’s nearly nose-to-nose with Lucifer. He swallows dryly. Lucifer’s face is completely neutral but Sam can feel a lurch in his stomach that’s all his own and _what the hell is going on?_

He fumbles for his phone and answers it.

“Dean?”

“Hey,” comes the grainy reply, “we’re headed back. Should be there by nightfall, if we don’t make any stops.”

“You guys both okay?” he asks, and sits up straight. His shoulder is still touching Lucifer’s and he steadfastly ignores it.

“Couple of scratches, nothin’ too bad.”

“Good,” says Sam. “See you tonight, then.”

“Yep.” They hang up and Sam yawns. Lucifer runs a thumb down Sam’s forearm and looks at him expectantly.

“They’ll should be home tonight,” he explains, then stands and stretches. “I’m gonna go make some food.”

Lucifer stands up with him and Sam pauses, eyebrows twitching together slightly. There’s something coiled tightly in Lucifer’s bones, something strong and vast and unnamed, something that Sam finds himself scared of because it shouldn’t be there. Lucifer slides a cool hand around the side of Sam’s neck, thumb resting lightly on his jaw, and then there’s a burst of white and Sam’s world expands.

Lucifer fills the entire room, the entire _house_ , glorious brilliance spilling out into the street and the city and painting everything with his light. The threads between them have kept growing stronger and stronger, winding around themselves, and now they’re thick, bright cords that bind them together and wrap them up into one being.

Sam-Lucifer’s consciousness expands and he-they can see the twin pinpricks of light that are Dean and Cas, glowing strong and warm and familiar while hurtling down a tiny two-lane highway. He-they fold back in on him-themselves and Sam feels the brush of intangible wings surrounding him with light and fury and storm. The vastness in Lucifer’s bones uncoils and it _burns_ through Sam like a wildfire, racing through his veins, nameless and terrifying and tangible and somehow completely perfect. When Lucifer withdraws, Sam’s trembling and the only logical thing for him to do, somehow, is to stumble even closer to Lucifer and pull him into a rough approximation of a hug. He feels numb and overwhelmed and _something_ , something that’s an echo of the nameless, patient coil that Sam realizes is in him, too.

Lucifer is at a loss for what to do, for a few seconds, and then one hand slides up into Sam’s hair and the other wraps tightly around his back. Sam’s got no idea how long they stay like that. He’s still got the residual tingle of the other dimension (or whatever the fuck it is, he still isn’t sure) buzzing in his hands and he can still feel the burn of that _something_ in his veins and for some fucking reason, it feels like they’re comforting each other – but he’s got no idea why. He lets his forehead drop to Lucifer’s shoulder and breathes in slowly, lets that all-too-familiar smell fill his nose.

He should be worried.

He should _really_ be worried, because things have definitely started crossing a sketchy line with Lucifer and they’re possibly maybe headed into extremely bad and terrifying and possible possibilities that Sam doesn’t want to consider.

At least not right now.

 

* * *

 

Dean slams a gallon-sized milk carton full of what looks like sloshy tar onto the kitchen table.

“There you go,” he says, “one jug of fresh Leviathan goo.” Lucifer picks it up and holds it up to the light, turns the jug a couple different ways, then puts it down again.

“I think that’ll be enough,” he says and Sam can feel his thoughts whirling in about seventy different directions, checking and double-checking. He picks up the jug again and walks into the library, still deep in thought, and a couple of seconds later he can hear paper rustling.

“How’d it go?” asks Sam. Dean sinks into a chair and shrugs.

“Normal,” he yawns. “Bastard didn’t want to squeal on his superiors so we iced and bled him. Shit’s nasty.” Sam huffs a laugh.

“Cas okay?”

“Yeah,” says Dean. “I was worried for a bit because the chomper got a few hits in, but Cas is tough.” He sounds kind of proud as he says it, like a dad at a soccer game. Sam tries not to grin; Dean stands up, then hesitates at the doorway.

“Sam,” he starts, and Sam’s stomach plunges because he knows something generally iffy is going to come next. “When this whole... mess is over, what’s gonna happen to you?” He turns back around and does his best not to meet Sam’s eyes. “I mean, last time we got a free ride to Heaven and Cas thinks that’s what gonna happen again – but you said part of what’s keeping Satan on our side is that if you die, then you’re both back in the Cage.” Sam swallows thickly.

“Yeah,” he says, “I, um– Lucifer said it’s 50/50, either we’re both back in the Pit or I’m yanked upstairs.”

Dean runs a hand down his face, and when he looks up his eyes are wrecked.

“Isn’t there– I don’t know, can’t you be sure?”

“Dean, it’s okay.” The look on Dean’s face is _professionally_ skeptical. “No, really. Even if I’m back in the Pit, it’s not– I mean, it’s gonna be different.” He shrugs and finds himself subconsciously looking towards the library. “Things aren’t really the same when you’ve got the Devil on your side.”

Dean gives him a long, searching look, and he gets the feeling that Dean can see something that he can’t.

“Okay,” he says quietly. “Nothin’ you can do about 50/50, right?” Sam nods, more to himself than to Dean. “I’m gonna go hit the sack. Night, Sammy.”

There’s a worldly tiredness to his voice and his footsteps are slow and heavy on the stairs.

 

 

A bright spark of surprise pulls Sam out of his accidental nap on the couch.

It’s well past 11:30, nearly midnight; he rubs his eyes and does his best to hear what’s going on in the library. Cas and Lucifer are talking, voices quiet, and Cas sounds terrible – small and full of doubt. He can’t make out exactly what they’re saying, but he gets the gist of it from Lucifer. Cas is _scared_ , and he’s scared for himself, for the first time that Sam can remember. He’s asking Lucifer where he’s going to end up, after all of his royal fuckups; Sam can only hear a quiet rumble from Cas, but Lucifer’s response is crystal-clear, both in his ears and his heart.

“You’ve fought against Heaven, Castiel,” Lucifer says. “You’ve fought for free will with the two doofuses, and you’ve ripped it away with your little god stunt – but somehow, you’ve managed to stay pure-hearted. I can see it in you. The two of us, we’ve been forged by our own actions, not by fate.” There’s a pause, heavy and full, and Lucifer’s voice goes soft. “I don’t know if Heaven’s got a place for outcasts like us, but if there’s a place for Thing 1 and Thing 2, then–” The semblance of a shrug ripples through Sam. “I’ve got no idea.”

Cas murmurs a thank you and Sam quickly pretends to still be asleep as he makes his way upstairs. He waits twenty, thirty heartbeats for the sound of a closing door then gets up from the couch, feeling oddly dazed. Lucifer is leaning against the front of the desk, arms crossed; Sam walks up to him and, in an only _slightly_ uncharacteristic gesture, takes Lucifer’s face between his hands and pulls their foreheads together. The stubble is rough against his palms, the skin cool, and Sam doesn’t know how to voice any of his thoughts but he knows Lucifer can feel them.

“What’s next?” he asks quietly, and for some reason, he’s afraid of the answer. Lucifer uncrosses his arms.

“Next I go to Wyoming,” he answers. “Tomorrow morning.” Sam feels like a fist has wrapped itself around his throat. Lucifer makes an apologetic face. “The sooner we get this done, the better.”

Sam backs away, just a little, and nods, more in self-assurance than in understanding. He does his absolute damn best not to freak out. There is _so much_ to process – this whole thing, it could all be over in a handful of days. He almost _wants_ it to be over with, and that in itself is a disturbing thought.

On the other hand, though, he’d once been prepared to live eternity in damnation to save the world. He can do it again.

 

 

Most of the time, Sam can push it to the back of his mind and convince himself that everything’s as normal as can be for a hunter. He doesn’t think about the frightening progression of his and Lucifer’s – he refuses to say relationship of any kind, so _vessel-hood_ , and he doesn’t think about the way they’re seamlessly, freakishly in tune with each other, or the way they’re practically got a permanent mind-meld going on.

It’s at night that he can’t escape it.

Not when they’re curled around each other and Lucifer is doing his _thing_ where Sam can see the world as he sees it, not when Sam has a hand buried in messy blonde hair, not when that stupid, irritating word ‘soulmate’ is banging around so loudly in his head that he thinks the neighbors can hear it. It’s scary as _shit_ but Sam’s well on the road to accepting it for what it is – they all might be full on doing their ‘fuck destiny’ thing, but when two people (well, arguably _people_ in the plural) so obviously fill each others’ cracks, it’s a little hard to argue with that tiny piece of the ineffable plan.

So Sam sighs and feels every molecule in his body shifting to accommodate the exhalation, synapses firing and mitochondria pumping, sodium-potassium channels flaring open and closed. Lucifer’s soul-Grace-being hums and a tangible-yet-intangible wing curves around his back, sparking and flaring where it meets corporality. He withdraws and pulls everything back into its other dimension; Sam is left feeling exceptionally empty and exceptionally flat, propped up on one elbow and watching Lucifer’s fingers tap out a rhythm on his other palm.

“How long is it gonna take?” Sam murmurs. Lucifer doesn’t need context but he pushes the thoughts out anyways, Samuel Colt and the Devil’s Trap and Wyoming and gone and alone; he knows Sam’s silently begging not to be without him.

“I’m a part of you, Sam,” says Lucifer quietly, and lays a hand right over Sam’s heart. Every single atom, every molecule and up-quark and Higgs boson leans into that touch, practically singing at the contact. “You will never be without me.”

It sort of scares Sam that he’s _not_ scared.


	13. Chapter 13

Sam wakes up alone.

He scrambles out of bed almost immediately because it feels wrong to wake up without someone next to him (he’s firmly avoiding the phrase ‘waking up next to Lucifer’ in his head) so he’s going to try and ignore the fact that it feels like someone pulled out his organs and replaced them with cotton.

He’s downstairs before Cas, which is saying something because Cas is _always_ up the earliest. He stares at the percolator, opens the cupboard, closes it again, and slumps into a chair. A couple minutes later he can hear footsteps in the hallway upstairs and he hauls himself back out of the chair, debates for a second, then grabs a jacket and tugs on a pair of boots. He doesn’t feel like dealing with Cas or Dean right now.

The walk to Cat’s Cradle is irritatingly cold and lonely. Lucifer’s presence is a dull wisp in his core, tugging him west-south-west towards his missing half. Sam stops mid-step, shakes his head, and resolutely forgets that the thought of Lucifer being his ‘other half’ ever crossed his mind. He ends up caught in the morning rush and waits in line behind four other people before he’s greeted by Marie’s grin.

“All alone today?” she asks, already scrawling his name on a cup, and then she takes a good look at him and frowns. “Geeze, Sam, you don’t look so great. Did you even sleep last night?” Sam frowns right back.

“Yeah, I–” He exhales and rubs the back of his neck. “Luce is outta town, so...”

He can’t possibly make that sentence any more awkward than it is, so he reaches into his pocket for his wallet. Marie’s got a funny look on her face, something shrewd, like she’s looking right through him.

“On the house,” she says, smile flickering back up onto her face. “I know how much it sucks to have your guy out of town, trust me.”

“My what?” Sam asks blankly, and when Marie makes an _oh shit_ sort of face it clicks. “Oh, no, it’s not–”

“Holy shit, I’m so sorry,” she whispers, terrified, looking over her shoulder in case her manager is paying attention. “I shouldn’t have assumed, it’s just–” Sam laughs awkwardly and runs a hand through his hair.

“No, it’s okay, really,” he says, because Marie looks like she’s on the verge of a panic attack. “Seriously, it’s happened before, it’s–it’s fine.” Technically true. Well, okay, he and _Dean_ have gotten snide comments in the past but same thing, really.

“Still, I’m really sorry,” she says mournfully, and resumes filling his cup. “You guys just kinda have this thing where you’re really, like, _in tune_ with each other, and–” She shakes her head. “Man, that was really rude of me. I’m sorry.” She hands him the coffee.

“We’ve, uh– we’ve known each other for a long time,” Sam explains. “So... yeah.”

 _Also_ technically true. Time moves differently in Hell but hey, it’s all the same in the end. She gives him a tentative smile.

“Still sucks to have someone you care about gone.”

 

Sam tries his best not to dwell on it. He really does. He doesn’t want to think about how much he’s missing Lucifer’s presence and the hum in his bones and how it’s different from when he misses Dean because it’s like someone’s taken away half of his body, expecting him to learn how to function with half the brainpower.

He buys a couple of books – _20,000 Leagues Under The Sea_ and a cool-looking copy of _To Kill A Mockingbird_ and something called _Good Omens_ the cashier had recommended – and he loses himself in fictional worlds for the whole day in order to forget that he feels completely numb. At least Cas and Dean are smart enough to leave him be.

 

* * *

 

Something’s been weighing heavily on Cas’s mind, and it’s driving Dean crazy. He’s been quieter than usual and he’s sort of curled in on himself and there’s a closed look on his face, so when he hears Cas moving around in the kitchen, Dean closes his book and walks in.

He watches Cas for a couple seconds – his movements are sharp and calculated but somehow graceful too, as he grabs a mug and drops a teabag in it, then lights the burner underneath the tea kettle. Dean then does something very un-Dean-ish and runs his palm down Cas’s shoulder, kisses the back of his neck, lets himself half-melt into his back. Cas is trembling.

“Cas?” he says quietly, trying his best to keep the sharpness of worry out of his voice.

“I’m feeling remorse,” comes the barely-whispered response. “This is definitely remorse. Dean, it _hurts_ , and it's getting harder and harder to push it–”

Dean turns him around by the shoulder and without another thought, kisses him. This whole thing is _very much_ un-Dean-ish but he doesn’t care, just pulls Cas as close as he can and tries to stop him trembling.

“Remorse is all about hurting, sweetheart,” he murmurs into Cas’s hair. “And hurting’s what being human’s all about, too.”

“It’s not that I was never sorry earlier–” Cas is trying to be indignant but it’s not coming across at all; his voice sounds small and broken, muffled against Dean’s shoulder. “–but I dwell on this every single day and it _hurts_ , that I hurt you and I hurt Sam.” Dean’s rubbing slow circles into Cas’s back, letting him talk it out even if it’s all babble. “I don’t know how you could possibly forgive me; I can’t even begin to consider forgiving myself. And the Leviathans are going to destroy everything, destroy the entirety of this Earth–” He suddenly pushes himself away from Dean with a horrified look on his face. “I have nearly helped unmake God’s creation.”

“Cas,” says Dean firmly, “ _relax_. Everyone makes mistakes. Some of us worse than others. I mean, hell, look at what Sam and I did, starting the Apocalypse. But we fixed it, Cas, and we’re going to fix this, too.” This time it’s Cas who lurches forward to clumsily kiss Dean, hands curling desperately into cotton.

“Being human sucks,” Dean murmurs, “it’s full of shit and it hurts but that’s why we have family.” He kisses Cas’s temple. “It sucks a little less this way.” Cas is nearly cutting off his air at this point, his arms are that tight. He can feel the rapid, ragged expansion of Cas’s ribcage against his, short staccato breaths against his neck. Footsteps creak on the stairs.

 

Sam thinks he might be hallucinating.

He’s halfway down the stairs and craning his neck to try and figure out what’s going on in the kitchen, because that’s definitely _not_ his brother down there, hugging the shit out of Cas – letting someone fall asleep on him is one thing for Dean, but hugging is an awkward affair with him at best and he can count on one hand the amount of times he’s seen him hug someone other than family. He takes another step and yeah, okay, that’s Dean and Cas and they’re hugging and Dean is giving him the biggest _get the fuck out of here, right the fuck now_ glare he’s ever gotten.

It takes him a split second to realize that Cas looks very much _not okay_ – he can tell by the way his shoulders are shaking that he’s either crying or hyperventilating, and this situation is getting weirder and weirder. Sam puts up his hands in defeat and silently retreats back up the stairs.

What surprises him is that this is making him _lonely_. Or rather, loneli _er_. Lucifer’s absence is like a lingering headache without a cure, constantly lurking in the back of his mind. It’s the first time he’s been without the Devil for more than a day in nearly five months and he’s trying hard not to let it drive him crazy.

He slumps down broodily into his bed; it’s past ten so he _might as well_ go to sleep, since there’s fuck-all to do. He’s halfway out of his jeans when the realization hits him that _Lucifer is still an angel_. His jeans manage to get tangled and he nearly falls in his haste to get them off. He shifts his weight awkwardly for a few moments – this feels like one of the dumbest ideas he’s ever had – then he clears his throat and puts his palms together.

“Uh, dear Lucifer,” he starts, and winces at how stupid he sounds. “I pray that you’re, um, doing okay. Over there. I guess.” He clears his throat again. This is obviously not going anywhere and he’s only going to put himself in an even worse mood, but he goes on anyways. “I just– uh, it’s kinda lonely here. Without you. So... come back soon. Amen.” Sam takes a good look at his choices and realizes he just prayed to the Devil. Yeah, his life is definitely _normal_.

A full minute passes. Nothing happens.

Lucifer is probably knee-deep in spellwork and Sam is about to give it up as a lost cause when a wave of pure emotion slams into him and he actually, physically stumbles back at the sheer force of it.

It’s _unbelievable_ , a heady mixture of gratitude and warm surprise and contentment and affection and something that Sam is very, very scared to consider putting a name to. It wraps itself around Sam like some kind of safety blanket made out of soft light and sleeping in and home-cooked meals and he practically falls into bed, euphoric and dazed. It’s like a shadow of what it feels like when Lucifer lets him in; he can’t see everything, but the sense of vastness and light and warmth and _oneness_ is all there. Every trace of loneliness is gone.

There’s one last, tiny thought that comes to him before he tumbles into a blissful sleep – that in all these millennia, Lucifer has never been prayed to, not as an angel, not by someone who actually cares, and it both warms Sam and saddens him that he’s the first.

 

 

Sam has less than a half-second’s warning, a dazzling flare that wakes him up as it burns through his bones, when there’s a soft flutter in the corner of the room. Before he can even realize what he’s doing, he’s throwing the covers off and he nearly runs.

“Lucifer, _jesus_ –”

And it feels so _right_ , to just roughly grab him and dig his fingers into the soft cotton of his button-up and breathe in the coldness-freezing-ice smell of him. He’s never so acutely felt the absence of someone, not even Dean, and being reunited with what is essentially his other half (not gonna think about it, not right now) is leaving him reeling and dizzy.

“Sam,” murmurs Lucifer, amusement curling through his voice, patiently dealing with the fact that Sam is clinging to him like his life depends on it. It takes Sam a couple of minutes to calm down and when his breaths even out, he curls a fist into Lucifer’s shirt and steps back toward his-their bed with a wordless plea. Lucifer follows him with the shadow of a smirk, something that’s not quite a soft smile because the Devil just doesn’t _do_ that kind of thing. For someone who runs cold, Lucifer’s body still manages to have its own brand of body heat, pressed in a comfortable line against Sam.

“Miss me?” says Lucifer quietly, and Sam can feel the tickle of stubble against his forehead, the slight chill of his lips.

“Shut up,” he replies, warmth spreading through his bones, and Lucifer just pulls him closer.

“You prayed to me,” murmurs Lucifer after a couple of minutes pass.

“Yeah,” Sam mumbles, feeling cool neck-skin under his mouth. “Was– is that okay?” Lucifer’s quiet laugh rumbles against him.

“You have no idea,” he whispers, “no _possible_ idea of knowing what it feels like to be prayed to.” Lucifer has one hand dug deep in Sam’s hair, practically crushing them together with the other. Sam realizes absently that he’s hanging on just as tightly, pushing himself close, desperately inhaling the way he smells, feeling the _realness_ under his palms and against his body, so mind-bendingly glad to have something tangible to hold on to, for once.

A distant part of his mind is laughing its ass off at this because it’s like a bad scene from a cheap romance novel, but he firmly reassures himself that there’s nothing like that going on. There’s no romance in the safety he feels when he buries his face in the Devil’s shoulder, no romance in the fingers rubbing a slow circle into the base of his neck, no romance in the faint brush of a mouth at his temple, no romance in the way he feels utterly, stupidly complete, with the Devil lying by his side.

 

* * *

 

Lucifer calls them all together the next morning.

“Unfortunately,” he prefaces, “this spell needs to be performed at dawn. It’s not as tasteless as ‘the stroke of midnight,’ but still.” He pulls a sheet of paper out of his pocket and unfolds it. “This is Old Enochian for ‘Leviathan.’ I’m going to use their blood to draw the sigil on each of you.” Dean makes a face. “The spell will call the lot of ‘em into the space laid out by the railroad, and by the time I’m through they’ll be gone and you’ll be sleeping on a cloud.”

Sam swallows thickly.

“So...” he starts, and then his throat closes and he _can't._

Lucifer looks at him and answers the question Sam couldn't finish.

“Tomorrow,” he replies. Dean tenses visibly; Cas takes a deep breath. “Set your alarms, boys. Tomorrow we save the world.”


	14. Chapter 14

“It’s incredible,” Lucifer murmurs into the hollow at the base of Sam’s neck.

“What is?”

“The amount of things you can learn by hanging around you and your brother.” Sam waits for him to continue his train of thought. “Castiel is obviously Exhibit A here, but I can’t say being around you knuckleheads hasn’t changed my mind about some stuff.”

“Is this one of those last-night-on-earth things?” asks Sam around a yawn. He’s just about ready to knock out, but at the same time he’s scared that this could be one of their last conversations – and tortured or not, Devil or not, Sam knows he’d be absolutely fucking _miserable_ without Lucifer. He doesn’t know whether he’d prefer being thrown in the Pit or being sent to Heaven because it’s metaphysically impossible for him to choose between Lucifer and Dean. He wonders when things got to this point.

Lucifer mulls his ideas around a bit before answering, and Sam can feel it like a rolling cloud bank in his core.

“If I were to snap my fingers and return to the moment you released me, knowing what I know now, I doubt I’d go through with the Apocalypse,” Lucifer says, nonchalant and casual in every syllable. Sam is speechless. “Well, it’s not really that I give two shits about humans,” he corrects off-handedly, “but yours and Dean’s whole screw destiny thing? I can dig that.”

Sam can’t even string a coherent thought together. Lucifer has never lied to him – by omission, maybe, but there is always truth in his words and his gut is telling him that this is absolute, no twists and nothing left out.

“But–”

“Oh, go to sleep,” Lucifer interrupts impatiently. “You can scratch your head over it tomorrow.” And with that he pushes himself up to kiss the center of Sam’s forehead, like a blessing, and then curls himself back under Sam’s chin.

He lies awake for a long time after that, listening to Lucifer’s quiet breaths and trying to pick apart the knot of feelings in his chest.

 

* * *

 

Lucifer, at least, has the sensibility to use a brush instead of fingers to paint the sigils – one on the back of each hand, black goo that’s inkier than tar or asphalt. Dean refuses to look anyone in the eye. Cas is standing straight and tall and _proud_ in the kitchen and he’s honestly the only thing keeping Sam from dissolving into a nervous mess. Lucifer finishes the last curl on his hand and Sam flexes it, watching the inky blood-stuff glisten with a sort of detached interest.

“Any last words?” says Lucifer quietly.

Sam looks up to find Dean staring at him imploringly and it’s _terrifying_. He can’t swallow around the lump in his throat and he lurches forward to hug his brother, even though Dean hates affection and hugs and Things To Do With Feelings. He’s warm and solid and god fucking _damn_ it, Sam is not going to cry. Dean pulls back and claps a hand to his shoulder, then gives him a horrible, maudlin approximation of a smile. Sam looks behind him.

“Cas–” he starts, then his voice gives out and he finds himself with an armful of ex-angel.

He really hopes God isn’t enough of a douchebag to not grant Cas entrance to Heaven after this because Jesus H. _Christ_ in a handbasket, he is literally doing the biggest possible ‘penance for his sins’ thing he can by giving up his life. They _all_ are. He gives Cas a tight smile and a short nod.

Lucifer snaps his fingers.

 

 

Wyoming is just as depressingly barren as it used to be, and the second they appear Sam feels a ripple of power, the spell recognizing its creator and its sacrificial lambs.

“Stay on this of the line,” warns Lucifer, as a strip of the ground in front of them flares a dazzling gold, and then he spreads his hands. “See you on the other side, boys.”

Enochian spills from his mouth, harsh and musical and _oh_ , Sam feels his hands tingling with it. He looks over at Dean and Cas to see them staring determinedly forward.

A low hum is building up; wind starts blowing against his face, gently at first, but it quickly develops into a gale the more Lucifer talks. He gets flashes of what the Enochian means – Lucifer talks about summoning and calling, of a binding tight and impenetrable. The hum explodes into something louder than a thunderclap and there’s an inhuman shriek as thousands of copied bodies are suddenly thrust into being; the line flares even brighter and Sam knows the Leviathans can’t cross it as they scream and fight, throwing themselves at the boundary of their prison.

Dick Roman stands directly opposite Lucifer, less than three feet and the line separating them, wearing the smirk that Sam hates so much. He can _feel_ Dean tense next to him. Lucifer finishes his sentence and everything is much, much too quiet.

Sam can’t hear wind or the crunch of dead grass or the rustling of his clothes as he reaches out, suddenly four years old again, to curl his palm against Dean’s. Cas’s knuckles are stark white against Dean’s other hand.

“So,” says Dick, “the tantrum child wants to play.” Lucifer smiles right back at him and Sam’s never been more terrified in his life when he realizes that he’s in the dead-center of a fight between _the fucking Devil_ and the most feared Biblical monster ever, of all time. ‘Small’ and ‘insignificant’ don’t even begin to cover it.

“Destroying the earth was supposed to be my thing, _Dick_ ,” Lucifer replies easily, and then starts up the Enochian again, slower this time, each syllable pounding with power. The Leviathans are practically crawling over each other and all Sam can see is Dick’s rage-flushed face, convulsing every few seconds into a monstrous mouth made more of teeth than flesh.

The sigils are starting to _burn_ on his skin; he just clings to Dean’s hand even tighter, reaches out with his other hand and finds Lucifer, twists his fingers between the Devil’s and hangs on for dear life. Behind them, the railroad that binds them all is glowing white-hot, building slowly into a blinding glare, and between that and the too-bright line in front of them, Sam can feel himself slipping away so he only holds on tighter, to his brother and his angel and his devil-other-half-soul-mate-bond, his _family_ , hoping against hope that he’s not going to lose everything.

There’s a loud, high-pitched whine that’s building and building and building and Sam’s reminded of when they called Michael down to Adam and he can feel Dean’s calloused hand and Lucifer’s cool one and a hot, desperate flare in his bones and everything’s much too bright, there’s too much white everywhere, and then–

 

 

 

Nothing.


	15. Chapter 15

He’s not sure if he wakes up or appears or comes to but the blinding white eventually fades to a nothingness of sorts, emptiness pressing in on him from every side. He thinks he’s lying on his back so he tries standing up but nothing looks different from his feet – same emptiness, everywhere, endless.

“Sam?” His voice sounds hollow, too loud and too quiet at the same time. “Sammy? You here?” Panic races through his chest at the thought of Sam being back in the Cage, of being stuck in Heaven without Sam or Cas for the rest of eternity.

Time doesn’t feel the way it normally does, because at one point in the future or maybe in the past or maybe in-an-hour-ago he turns around and sees a dark shape behind him.

“Sammy?” He’s hoarse from yelling, but the shape turns and starts jogging towards him and yeah, that’s definitely his brother. He could cry with relief when Sam’s giraffe arms loop around him; his brother smells like clean laundry and gun-cleaning oil, the same way he’s always smelled. He pulls away and something’s _off_. Sam looks like someone’s chopped off one of his limbs – empty, more than a little broken, like he’s trying to make up for the loss of something. It takes Dean a couple of seconds to realize that Lucifer isn’t around here and he wonders whether that’s it – they definitely had some kind of vessel connection going on, and he can only hope it hasn’t taken a toll on Sam. He doesn’t deserve something like that, even if it’s Lucifer that’s in question.

“Dean, thank god,” Sam says. His voice is wrecked. “Or– I don’t know, is that blasphemy up here?”

“I don’t think He minds,” comes a new voice, and Dean whirls around to see Cas standing in front of them. Cas, Castiel, _his_ Cas, with the slightest hint of a smile on his face and instantly Dean _knows_.

“Cas, you’re– are you an angel?” he sputters, incredulous. He’s wearing his old trenchcoat over a pair of familiar jeans and dark flannel and a gray t-shirt and he’s never looked better. Cas’s smile widens, barely-just-barely.

“Someone saw fit to restore my rank,” he says, warmth in his voice. “It seems I’ve learned my lesson.” Dean doesn’t care that his little brother is watching. He doesn’t care that he’s in Heaven (or some kind of limbo, he’s still not sure). All that matters is that he grabs Cas by the lapels of that damned coat and kisses him, strong and deep, because it’s the right thing to do. Sam makes a quiet noise of amusement behind him; Dean just slides a hand round the back of Cas’s neck and keeps going. Sam pointedly clears his throat.

“Cas, where are we?” he asks, and Dean forces himself out of Cas’s personal space for the sake of politeness.

“Outside the gates of Heaven,” he responds, and the back of his hand brushes against Dean’s. There’s the tiniest discharge of static electricity. “I requested to be the one to lead you both in.”

The shadow of a grin flits across Sam’s tired face.

“Thanks,” he says, and his voice sounds a tiny bit brighter.

 

* * *

 

Heaven’s not so bad this time around, he thinks. He and Sam wander off in their own directions for a while, and Dean spends maybe a day, maybe a year, reliving every tiny moment that he loved. Watching Sam shoot a neat line of bullet holes into a target, getting tucked in by Mom, fixing up the Impala, driving it for the first time. Cas flits in and out of his memories and he spends another hour-day-decade with him, sometimes drinking in his quiet breaths, sometimes screaming his name as his mind blissfully blanks out with the rush of orgasm. His life feels complete, for once – he feels like he hasn’t died in vain. Cas tells him that things on earth are shifting back into their normal balance sans Leviathans and Dean feels a sort of serenity and peacefulness he’s not sure he ever felt before.

He eventually persuades Cas into leading him and Sam back into Ash’s heaven. It’s exactly like it was the last time – same old Roadhouse, same angel-radar computer, same bar, same Ash.

“So how’d you end up here this time, amigos?” drawls Ash, chugging a can of cheap beer and leaning onto his elbows. The jukebox is softly playing _Going To California_ and hey, this is Heaven, so Dean mentally lines up a playlist of his favorite songs to come next. Sam chuckles.

“Man, you probably wouldn’t believe us if we told you,” he says. Ash shrugs.

“Easier to believe stuff when you’re dead,” he responds neutrally. “But hang on a sec, someone’s on their way to see you guys.”

 

 

Sam’s jaw drops and the next thing he knows, he’s barreling forward and pulling Jo into a tight hug. Ellen has to actually yank Dean off of the bar stool because he’s frozen, but then he melts and wraps Ellen up in his arms. Jo pulls away and gives him a watery smile, and then claps Dean on the shoulder. Sam lets himself get pulled into a rough hug by Ellen and smells food and beer and woodsmoke on her.

“We were hopin’ you boys would have a couple more years on us,” she says sternly. “And Castiel, we heard some rumors about you that better not be true.”

Cas ducks his head; Sam catches Dean subtly reaching out to him. Jo pulls a beer out from behind the bar and cracks it open.

“So,” she starts, “you wanna tell us what’s been happening? We don’t know how reliable the grapevine is ‘round here.”

 

 

He’s got no idea how long it actually takes to fill them in on everything, from that night in Carthage to the Horsemen’s rings to being in the Cage to being back out to Cas’s brief god-hood to the Leviathans to Lucifer to the vampires to the spell. There are approximately forty empty beer bottles he’s responsible for, but he’s still only pleasantly buzzed. One of the many perks of being dead, he supposes.

The story has broken down into aimless conversation between the six of them and Sam sits back, watching Cas animatedly tell the story of how Dean tried to get him laid via hooker. Dean’s laughing and watching every move that Cas makes with a sort of softness in his eyes that Sam hasn’t seen in decades – since before he left for Stanford, probably. It feels good to see him happy and hell, Cas is awesome. Cas is _more_ than awesome. Ash is listening to them with one ear, using the majority of his attention to tweak something on his laptop.

And then, three things happen at once:

Cas goes stock-still, eyes wide, and within a second there’s the loud snap of wings and he’s gone.

The computer starts beeping frantically, accompanied by a chorus of colorful curses from Ash.

And Sam nearly _passes out_.

His bones are on fire and he’s never felt anything like this – a pleasure so immense that it almost _hurts_ and his core is burning so fiercely that he thinks he’s going to disintegrate and he realizes he’s on his knees, clutching futilely at his chest and Dean is yelling and Ash is yelling and Jo is yelling and Ellen is yelling and then somehow, through the din, an impossibly familiar voice cuts above everyone else.

“Hi, Sam.”

It’s not possible.

It’s _not possible_ because he felt the connection die when the whiteness swallowed everything – like a sword cutting through all the cords binding them – and he’s been a half-soul for all this time and it’s not _possible_ that Lucifer is standing in the middle of the Roadhouse as Sam hauls himself to his feet, still shaking. Dean grabs his elbow and helps him up; the silence is deafening.

Lucifer is still smiling, that same easy smirk he always wears, and he walks over and opens the door expectantly. There’s empty nothingness outside.

“Shall we?” he says.

Sam is absolutely past the point of functioning so he barely registers Dean’s palm shoving him gently forward until he stumbles out of the Roadhouse and the door quietly snaps closed behind him.

He’s got no idea how much time they spend staring at each other, and then he finally regains enough control over himself to break the silence.

“It’s really you?” he whispers, hoping against hope.

Lucifer’s smirk melts into something softer and everything suddenly lines up for Sam. He crosses the distance between them in three long strides and kisses him.

It’s weird. _God_ , it’s weird that the Devil’s mouth is a perfect fit against his and the way he sighs into Sam and the curve of his jaw and most of all, it’s weird that this feels like the most natural thing to do. He doesn’t even know what to do with his hands for all of the four seconds it lasts, and he ends up with his fingers curled around one of Lucifer’s biceps.

“ _Well_ , Sammy,” he murmurs, “can’t say I was expecting that.” Sam’s bones are made of hot ashes and coal-fire and he pulls Lucifer into a rough, desperate hug.

“How– What ha–” He swallows and starts again. “ _How?_ ”

The emptiness dissolves and ripples and shifts and they’re back in _The_ House, their house – in Sam’s bed, under the same scratchy sheets, on the same lumpy mattress. Lucifer smiles and he looks exactly like a self-satisfied cat so, naturally, Sam grins back and kisses the smug smirk off of his face. Lucifer’s mouth is cool and soft and exactly like he’d imagined it to be.

 _Not_ that he’d ever thought about kissing the Devil.

“Are you gonna let me talk or keep me busy?” says Lucifer, lips curling up. “‘Cause I’m fine with either.” Sam pushes himself up onto one elbow.

“What happened?” he asks, trying to keep a stupid smile off of his face. There’s a hum deep-set in his bones and it’s flooding every inch of him with euphoria.

“I talked to my father,” says Lucifer quietly, trailing fingers down Sam’s side, resting barely under the hem of his t-shirt. He chuckles at the look on Sam’s face. “Michael too.”

“But how? Why?” Lucifer’s palm slides up under his shirt and Sam nearly forgets what he just said at the feeling of fingertips dancing lightly across his hipbones.

“He was testing me, you know,” he murmurs, and kisses Sam once, twice, until he’s breathless and the slightest bit dizzy. “He’s the one who let me slip out of the Cage with you. He wanted to see what I’d do, and I made the right choices.”

“Sacrificing yourself?” asks Sam. Lucifer shrugs.

“I learned from you and Dean,” he corrects. “Apparently Dad did a lot of thinking, too. We had a nice talk about our feelings. You know, hankies for everyone, stuff like that.” The next part is so quiet that Sam barely hears it. “He’s proud of me.” The happiness radiating from Lucifer is so strong and infectious that Sam grins in response, slings his body over Lucifer’s and kisses him until he can’t breathe.

“Me too, you know,” he murmurs. “Against everything you’re supposed to be, you did the right thing.”

And with a ferocious blaze of light and wings and Grace, Lucifer lets him in and Sam’s never felt more _perfect_.

“I know.”

**Author's Note:**

> Man, a big huge thank you to everyone who’s stuck around to the end! It makes me endlessly happy to watch the hit counter go up, one by one, so thank you from the bottom of my heart. This fic was a huge experiment for me – not only had I never written Sam (or Lucifer) before, but I’d also never written a multi-chapter fic with an actual plot. I’m glad to see that people are interested not only in what I have to say, but also in this pairing.
> 
> I mentioned some music throughout this fic – Metallica’s cover of Loverman, Nick Cave’s original, and twice Led Zeppelin: Stairway to Heaven, and Going to California. To be honest, Loverman is my ~anthem for Samifer and it’s worth a listen because a) good music b) reasons c) Samifer. Both versions are great but there’s something fantastically dark and seductive and sultry and exceptionally Samifery about Metallica’s cover.
> 
> Also, I started this fic after 7x15 and at the time I finished planning it out, the season still wasn’t over yet. This started out half a drabble and half speculation!fic – my predictions/hopes for this season around episodes 15-17 included the boys having to team up with Lucifer in order to get rid of the Leviathans. It’d have been a really interesting direction to take, to see them teaming up with The Bad Guy in order to get rid of the Leviathans, and I was super disappointed to see that they just waved Lucifer away after episode 17.
> 
> So, to wrap up the non-sequitur monster that this A/N has become, _thank you_. Seriously, thank you all so much for seeing this through to the end, and I hope you liked it.


End file.
